basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana BES1-interacting Myc-like proteins (BIMs) and similar proteins; The family includes Arabidopsis thaliana BIM1 and its homologs (BIM2 and BIM3), which are bHLH transcription factors that interact with BES1 to regulate transcription of Brassinosteroid (BR)-induced gene. BR regulates many growth and developmental processes such as cell elongation, vascular development, senescence stress responses, and photomorphogenesis. BIM1 heterodimerize with BES1 and bind to E-box sequences present in many BR-induced promoters to regulated BR-induced genes.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1002292294 220 NTPRSKHSATEQRRRSKINDRFQLLRDLLPHNDQKRDKASFLLEVIEYIRFLQEKVQKYEVSYPEWNQENAKVVPW 295
Cdd:cd11453     1 STPRSKHSATEQRRRSKINERLQALRDLIPHSDQKRDKASFLLEVIEYIQALQEKVAKLEEQVQGWGGEPAKLTPW 76

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana BES1-interacting Myc-like proteins (BIMs) and similar proteins; The family includes Arabidopsis thaliana BIM1 and its homologs (BIM2 and BIM3), which are bHLH transcription factors that interact with BES1 to regulate transcription of Brassinosteroid (BR)-induced gene. BR regulates many growth and developmental processes such as cell elongation, vascular development, senescence stress responses, and photomorphogenesis. BIM1 heterodimerize with BES1 and bind to E-box sequences present in many BR-induced promoters to regulated BR-induced genes.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1002292294 220 NTPRSKHSATEQRRRSKINDRFQLLRDLLPHNDQKRDKASFLLEVIEYIRFLQEKVQKYEVSYPEWNQENAKVVPW 295
Cdd:cd11453     1 STPRSKHSATEQRRRSKINERLQALRDLIPHSDQKRDKASFLLEVIEYIQALQEKVAKLEEQVQGWGGEPAKLTPW 76

helix loop helix domain;

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|
gi 1002292294  230 EQRRRSKINDRFQLLRDLLP--HNDQKRDKASFLLEVIEYIRFLQEKVQK 277
Cdd:smart00353   4 ERRRRRKINEAFDELRSLLPtlPKNKKLSKAEILRLAIEYIKSLQEELQK 53

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana BES1-interacting Myc-like proteins (BIMs) and similar proteins; The family includes Arabidopsis thaliana BIM1 and its homologs (BIM2 and BIM3), which are bHLH transcription factors that interact with BES1 to regulate transcription of Brassinosteroid (BR)-induced gene. BR regulates many growth and developmental processes such as cell elongation, vascular development, senescence stress responses, and photomorphogenesis. BIM1 heterodimerize with BES1 and bind to E-box sequences present in many BR-induced promoters to regulated BR-induced genes.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1002292294 220 NTPRSKHSATEQRRRSKINDRFQLLRDLLPHNDQKRDKASFLLEVIEYIRFLQEKVQKYEVSYPEWNQENAKVVPW 295
Cdd:cd11453     1 STPRSKHSATEQRRRSKINERLQALRDLIPHSDQKRDKASFLLEVIEYIQALQEKVAKLEEQVQGWGGEPAKLTPW 76

Helix-loop-helix DNA-binding domain;

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1002292294 223 RSKHSATEQRRRSKINDRFQLLRDLLPH--NDQKRDKASFLLEVIEYIRFLQ 272
Cdd:pfam00010   2 REAHNERERRRRDRINDAFDELRELLPTlpPDKKLSKAEILRLAIEYIKHLQ 53

basic Helix Loop Helix (bHLH) domain superfamily; bHLH proteins are transcriptional regulators that are found in organisms from yeast to humans. Members of the bHLH superfamily have two highly conserved and functionally distinct regions. The basic part is at the amino end of the bHLH that may bind DNA to a consensus hexanucleotide sequence known as the E box (CANNTG). Different families of bHLH proteins recognize different E-box consensus sequences. At the carboxyl-terminal end of the region is the HLH region that interacts with other proteins to form homo- and heterodimers. bHLH proteins function as a diverse set of regulatory factors because they recognize different DNA sequences and dimerize with different proteins. The bHLH proteins can be divided to cell-type specific and widely expressed proteins. The cell-type specific members of bHLH superfamily are involved in cell-fate determination and act in neurogenesis, cardiogenesis, myogenesis, and hematopoiesis.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 1002292294 230 EQRRRSKINDRFQLLRDLLP--HNDQKRDKASFLLEVIEYIRFLQE 273
Cdd:cd00083     1 ERRRRDKINDAFEELKRLLPelPDSKKLSKASILQKAVEYIRELQS 46

basic Helix-Loop-Helix (bHLH) domain found in Arabidopsis thaliana MYC1 and similar proteins; MYC1, also termed AtbHLH12, or EN 58, acts as a transcription activator, when associated with MYB75/PAP1 or MYB90/PAP2.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1002292294 226 HSATEQRRRSKINDRFQLLRDLLPhNDQKRDKASFLLEVIEYIRFLQEKVQ--KYEVSYPEWNQENAKVV 293
Cdd:cd18918     1 LFATERERREKLNEKFSDLRNLIP-NPTKNDRASILSDAIKYINELQRTVEelKSLVEKKRCGERDRKTT 69

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana phytochrome interacting factors (PIFs) and similar proteins; The family includes several bHLH transcription factors from Arabidopsis thaliana, such as PIFs, ALC, PIL1, SPATULA, and UNE10. PIFs (PIF1, PIF3, PIF4, PIF5, PIF6 and PIF7) have been shown to control light-regulated gene expression. They directly bind to the photoactivated phytochromes and are degraded in response to light signals. ALC, also termed AtbHLH73, or protein ALCATRAZ, or EN 98, is required for the dehiscence of fruit, especially for the separation of the valve cells from the replum. It promotes the differentiation of a strip of labile non-lignified cells sandwiched between layers of lignified cells. PIL1, also termed AtbHLH124, or protein phytochrome interacting factor 3-like 1, or EN 110, is involved in responses to transient and long-term shade. It is required for the light-mediated inhibition of hypocotyl elongation and necessary for rapid light-induced expression of the photomorphogenesis- and circadian-related gene APRR9. PIL1 seems to play a role in multiple PHYB responses, such as flowering transition and petiole elongation. SPATULA, also termed AtbHLH24, or EN 99, plays a role in floral organogenesis. It promotes the growth of carpel margins and of pollen tract tissues derived from them. UNE10, also termed AtbHLH16, or protein UNFERTILIZED EMBRYO SAC 10, or EN 99, is required during the fertilization of ovules by pollen.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1002292294 226 HSATEQRRRSKINDRFQLLRDLLPhNDQKRDKASFLLEVIEYIRFLQEKVQ 276
Cdd:cd11445     6 HNLSERRRRDRINEKMKALQELIP-NCNKTDKASMLDEAIEYLKSLQLQVQ 55

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in sterol regulatory element-binding protein (SREBP) family and similar proteins; The SREBP family includes SREBP1 and SREBP2, which are bHLHzip transcriptional activator of genes encoding proteins essential for cholesterol biosynthesis/uptake and fatty acid biosynthesis. SREBP1 and SREBP2 are principally found in the liver and in adipocytes and made up of an N-terminal transcription factor portion (composed of an activation domain, a bHLHzip domain, and a nuclear localization signal), a hydrophobic region containing two membrane spanning regions, and a C-terminal regulatory segment. They recognize a symmetric sterol regulatory element (TCACNCCAC) instead of E-box. The family also includes Saccharomyces cerevisiae transcription factor HMS1 (also termed high-copy MEP suppressor protein 1) and serine-rich protein TYE7. HMS1 is a putative bHLHzip transcription factor involved in exit from mitosis and pseudohyphal differentiation. TYE7, also termed basic-helix-loop-helix protein SGC1, is a putative bHLHzip transcription activator required for Ty1-mediated glycolytic gene expression. TYE7 N-terminal is extremely rich in serine residues. It binds DNA on E-box motifs, 5'-CANNTG-3'. TYE7 is not essential for growth.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1002292294 221 TPRSKHSATEQRRRSKINDRFQLLRDLLP--------------HND---QKRDKASFLLEVIEYIRFLQEKVQKYE 279
Cdd:cd11395     2 RKRLPHNAIEKRYRSNLNTKIERLRDAIPslrspegksddgglGGLaptTKLSKATILTKAIEYIRHLEQENERLE 77

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana protein ABA-INDUCIBLE bHLH-TYPE (AIB) and similar proteins; The family includes several bHLH transcription factors from Arabidopsis thaliana, such as AIB and MYC proteins (MYC2, MYC3 and MYC4). AIB, also termed AtbHLH17, or EN 35, is a transcription activator that regulates positively abscisic acid (ABA) response. MYC2, also termed protein jasmonate insensitive 1, or R-homologous Arabidopsis protein 1 (RAP-1), or AtbHLH6, or EN 38, or Z-box binding factor 1 protein, is a transcriptional activator involved in abscisic acid (ABA), jasmonic acid (JA), and light signaling pathways. MYC3, also termed protein altered tryptophan regulation 2, or AtbHLH5, or transcription factor ATR2, or EN 36, is a transcription factor involved in tryptophan, jasmonic acid (JA) and other stress-responsive gene regulation. MYC4, also termed AtbHLH4, or EN 37, is a transcription factor involved in jasmonic acid (JA) gene regulation. MYC2, together with MYC3 and MYC4, controls additively subsets of JA-dependent responses.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1002292294 226 HSATEQRRRSKINDRFQLLRDLLPhNDQKRDKASFLLEVIEYIRFLQEKVQKYE 279
Cdd:cd11449     9 HVEAERQRREKLNQRFYALRAVVP-NVSKMDKASLLGDAISYINELKSKVQDME 61

basic helix-loop-helix (bHLH) domain found in the spermatogenesis- and oogenesis-specific basic helix-loop-helix-containing protein (SOHLH) family; The SOHLH family includes two bHLH transcription factors, SOHLH1 and SOHLH2. They are specifically in spermatogonia and oocytes and essential for early spermatogonial and oocyte differentiation.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1002292294 224 SKHSATEQRRRSKINDRFQLLRDLLPHNDQKR-DKASFLLEVIEYIRFLQEKVQKY 278
Cdd:cd18908     4 SSHSLKERLRRERIKSSCDQLRDLLPYIKGRKlDMASVLEMTVKYIRYIQERIPPE 59

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in the microphthalmia-associated transcription factor family (MITF) family; The MITF (also known as microphthalmia-TFE, or MiT) family is a small family that contain a basic helix loop helix domain associated with a leucine zipper (bHLHZip). The MITF family comprises four genes in mammals (MITF, TFE3, TFEB, and TFEC); each gene has different functions. MITF is involved in neural crest melanocytes development as well as the pigmented retinal epithelium. TFEB is required for vascularization of the mouse placenta. TFE3 is involved in B cell function. TFEC regulates gene expression in macrophages. The MITF family can form homodimers or heterodimers with each other but not with other bHLH or bHLHzip proteins.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1002292294 226 HSATEQRRRSKINDRFQLLRDLLPHN---DQKRDKASFLLEVIEYIRFLQEKVQKYE 279
Cdd:cd11397     9 HNMIERRRRFNINDRIKELGTLLPKSndpDMRWNKGTILKASVDYIRKLQKEQERLR 65

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana Fe-deficiency induced transcription factor 1 (FIT) and similar proteins; The family includes bHLH transcription factors from Arabidopsis thaliana, such as FIT and DYT1. FIT, also termed FER-like iron deficiency-induced transcription factor, or FER-like regulator of iron uptake, or AtbHLH29, or EN 43, is a bHLH transcription factor that is required for the iron deficiency response in plant. It regulates FRO2 at the level of mRNA accumulation and IRT1 at the level of protein accumulation. DYT1, also termed AtbHLH22, or protein dysfunctional tapetum 1, or EN 49, is a bHLH transcription factor involved in the control of tapetum development. It is required for male fertility and pollen differentiation, especially during callose deposition.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1002292294 221 TPRSKHSATEQRRRSKINDRFQLLRDLLPhNDQKRDKASFLLEVIEYIRFLQEKVQKYEVSYPE 284
Cdd:cd11450     2 SPASKNLVSERNRRQKLNQRLFALRSVVP-NITKMDKASIIKDAISYIQELQYQEKKLEAEIRE 64

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana BIG PETAL (BPE) and similar proteins; The family includes several bHLH transcription factors from Arabidopsis thaliana, such as BPE, HBI1 and BEE proteins (BEE1-3). BPE, also termed AtbHLH31, or EN 88, is involved in the control of Arabidopsis petal size, by interfering with postmitotic cell expansion to limit final petal cell size. HBI1, also termed AtbHLH64, or homolog of bee2 interacting with IBH1, or EN 79, is an atypical bHLH transcription factor that acts as positive regulator of cell elongation downstream of multiple external and endogenous signals by direct binding to the promoters and activation of the two expansin genes EXPA1 and EXPA8, encoding cell wall loosening enzymes. BEEs, also termed protein Brassinosteroid enhanced expression, are positive regulators of brassinosteroid signaling.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|.
gi 1002292294 226 HSATEQRRRSKINDRFQLLRDLLPHNDQKRDKASFLLEVIEYIRFLQEKVQ 276
Cdd:cd18919    16 HSLAERVRREKISERMKLLQDLVPGCNKVTGKALMLDEIINYVQSLQRQVE 66

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in USF/MITF family; The USF (upstream stimulatory factor)/MITF (microphthalmia-associated transcription factor) family includes two bHLHzip transcription factor subfamilies. USFs are ubiquitously expressed and key regulators of a wide number of gene regulation networks, including the stress and immune responses, cell cycle and proliferation, lipid and glucid metabolism. USFs recruit chromatin remodeling enzymes and interact with co-activators and the members of the transcription pre-initiation complex. USFs interact with high affinity to E-box regulatory elements. The MITF (also known as microphthalmia-TFE, or MiT) subfamily comprises four genes in mammals (MITF, TFE3, TFEB, and TFEC); each gene has different functions. MITF is involved in neural crest melanocytes development as well as the pigmented retinal epithelium. TFEB is required for vascularization of the mouse placenta. TFE3 is involved in B cell function. TFEC regulates gene expression in macrophages. The MITF subfamily proteins can form homodimers or heterodimers with each other but not with other bHLH or bHLHzip proteins.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1002292294 226 HSATEQRRRSKINDRFQLLRDLLP-----HNDQKRDKASFLLEVIEYIRFLQEKVQ 276
Cdd:cd11387     2 HNAVERRRRDNINEKIQELGSLVPpsrleTKDLKPNKGSILSKAVEYIRELQNQNQ 57

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana protein INDEHISCENT (IND) and similar proteins; The family includes several bHLH transcription factors from Arabidopsis thaliana, such as IND, HEC proteins (HEC1, HEC2 and HEC3) and UNE12. IND, also termed AtbHLH40, or EN 120, is a bHLH transcription regulator required for seed dispersal. It is involved in the differentiation of all three cell types required for fruit dehiscence. HEC1 (also termed AtbHLH88, or protein HECATE 1, or EN 118), HEC2 (also termed AtbHLH37, or protein HECATE 2, or EN 117) and HEC3 (also termed AtbHLH43, or protein HECATE 3, or EN 119) are required for the female reproductive tract development and fertility. Both IND and HEC proteins have been implicated in regulation of auxin signaling. They heterodimerize with SPATULA (SPT) bHLH transcription factor to regulate reproductive tract development in plant. UNE12, also termed AtbHLH59, or protein UNFERTILIZED EMBRYO SAC 12, or EN 93, is required for ovule fertilization.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*
gi 1002292294 232 RRRSKINDRFQLLRDLLPhNDQKRDKASFLLEVIEYIRFLQEKVQ 276
Cdd:cd11454    11 HRRERISERIRILQRLVP-GGTKMDTASMLDEAIHYVKFLQLQVK 54

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in Max-like protein X (Mlx) family; Mlx, also termed Class D basic helix-loop-helix protein 13 (bHLHd13), or Max-like bHLHZip protein, or protein BigMax, or transcription factor-like protein 4, is a Max-like bHLHZip transcription regulator that interacts with the Max network of transcription factors. It forms a sequence-specific DNA-binding protein complex with some member of Mad family (Mad1 and Mad4) and Mondo family but not the Myc family and bind the E-box DNA to control transcription. The family also includes Saccharomyces cerevisiae INO4, which is a bHLH transcriptional activator of phospholipid synthetic genes (such as INO1, CHO1/PSS, CHO2/PEM1, OPI3/PEM2, etc.). It is required for de-repression of phospholipid biosynthetic gene expression in response to inositol deprivation in yeast.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1002292294 222 PRSKHSATEQRRRSKINDRFQLLRDLLPH-NDQKRDKASFLLEVIEYIRFLQEK 274
Cdd:cd11404     2 RRLNHVRSEKKRRELIKKGYDELCALVPGlDPQKRTKADILQKAADWIQELKEE 55

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in transcription factor AP-4 (TFAP4) and similar proteins; TFAP4, also termed activating enhancer-binding protein 4, or Class C basic helix-loop-helix protein 41 (bHLHc41), is a bHLHzip transcription factor that activates both viral and cellular genes involved in the regulation of cellular proliferation, stemness, and epithelial-mesenchymal transition by binding to the symmetrical DNA sequence 5'-CAGCTG-3'.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*....
gi 1002292294 230 EQRRRSKINDRFQLLRDLLPHND-QKRDKASFLLEVIEYIRFLQEKVQK 277
Cdd:cd11419    12 ERRRMQSINAGFQSLRTLLPHCDgEKLSKAAILQQTAEYIFSLEQEKTR 60

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in MAX gene-associated protein (MGA) family; The MGA family includes MGA, Schizosaccharomyces pombe ESC1 (spESC1) and similar proteins. MGA, also termed MAX dimerization protein 5 (MAD5), is a dual specificity T-box/ bHLHzip transcription factor that regulates the expression of both Max-network and T-box family target genes. It contains a Myc-like bHLHZip motif and requires heterodimerization with Max for binding to the preferred Myc-Max-binding site CACGTG. In addition to the bHLHZip domain, MGA harbors a second DNA-binding domain, the T-box or T-domain. It thus binds the preferred Brachyury-binding sequence and represses transcription of reporter genes containing promoter-proximal Brachyury-binding sites. spESC1 is a bHLHzip protein with homology to human MyoD and Myf-5 myogenic differentiation inducers. It is involved in the sexual differentiation process.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1002292294 223 RSKHSATEQRRRSKINDRFQLLRDLLP-HNDQKRDKASFLLEVIEYIRFLQEKVQK 277
Cdd:cd19682     1 RLRHKKRERERRSELRELFDKLKQLLGlDSDEKASKLAVLTEAIEEIQQLKREEDE 56

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in Max-like protein X (Mlx) and similar proteins; Mlx, also termed Class D basic helix-loop-helix protein 13 (bHLHd13), or Max-like bHLHZip protein, or protein BigMax, or transcription factor-like protein 4, is a Max-like bHLHZip transcription regulator that interacts with the Max network of transcription factors. It forms a sequence-specific DNA-binding protein complex with some member of Mad family (Mad1 and Mad4) and Mondo family but not the Myc family and bind the E-box DNA to control transcription.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1002292294 223 RSKHSATEQRRRSKINDRFQLLRDLLP---HND----QKRDKASFLLEVIEYIRFLQEKVQKYE 279
Cdd:cd19687     3 REAHTQAEQKRRDAIKKGYDDLQDIVPtcqQQDdigsQKLSKATILQRSIDYIQFLHQQKKKQE 66

basic helix-loop-helix-orange (bHLH-O) domain found in hairy and enhancer of split (HES)-related repressor protein (HERP)-like family; The HERP-like family includes bHLH-O transcriptional regulators that are related to the Drosophila hairy and Enhancer-of-split proteins. They contain a basic helix-loop-helix (bHLH) domain with an invariant glycine residue in its basic region, an orange domain in the central region and YXXW sequence motif at its C-terminal region. HERP proteins (HEY1, HEY2 and HEYL) act as downstream effectors of Notch signaling. They are involved in cardiovascular development and have roles in somitogenesis, myogenesis and gliogenesis. Hairy and enhancer of split-related protein HELT is a transcriptional repressor expressed in the developing central nervous system. It binds preferentially to the canonical E box sequence 5'-CACGCG-3' and regulates neuronal differentiation and/or identity. Differentially expressed in chondrocytes proteins, DEC1 and DEC2, are widely expressed in both embryonic and adult tissues and have been implicated in apoptosis, cell proliferation, and circadian rhythms, as well as malignancy in various cancers. Drosophila melanogaster protein clockwork orange (Cwo) is also included in this family. It is involved in the regulation of Drosophila circadian rhythms. It functions as both an activator and a repressor of clock gene expression.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 1002292294 226 HSATEQRRRSKINDRFQLLRDLLP----HNDQKR-DKASFLLEVIEYIRFLQ 272
Cdd:cd11389     1 HKVIEKRRRDRINESLAELRRLVPearkSKGSGKlEKAEILEMTLQHLKALQ 52

basic helix-loop-helix (bHLH) domain found in Saccharomyces cerevisiae protein INO2 and similar proteins; INO2 is a positive regulatory factor required for depression of the co-regulated phospholipid biosynthetic enzymes in Saccharomyces cerevisiae. It is also involved in the expression of ITR1.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1002292294 220 NTPRSKHSATEQRRRSKINDRFQLLRDLLP----HNDQKRDKASFLLEVIEYIRFLQEKVQK 277
Cdd:cd11388     1 PVKKWKHVEAEKKRRNQIKKGFEDLINLINyprnNNEKRISKSELLNKAVDDIRGLLKANEQ 62

basic helix-loop-helix (bHLH) domain found in Arabidopsis thaliana protein FAMA and similar proteins; The family includes several bHLH transcription factors from Arabidopsis thaliana, such as FAMA, MUTE and SPEECHLESS, which work together to regulate the sequential cell fate specification during stomatal development and differentiation. FAMA, also termed AtbHLH97, or EN 14, is a transcription activator required to promote differentiation and morphogenesis of stomatal guard cells and to halt proliferative divisions in their immediate precursors. It mediates the formation of stomata. MUTE, also termed AtbHLH45, or EN 20, is required for the differentiation of stomatal guard cells, by promoting successive asymmetric cell divisions and the formation of guard mother cells. It promotes the conversion of the leaf epidermis into stomata. SPEECHLESS, also termed AtbHLH98, or EN 19, is required for the initiation and the formation of stomata, by promoting the first asymmetric cell divisions. FAMA, MUTE and SPEECHLESS form heterodimers with SCREAM/ICE1 and SCRM2 to regulate transcription of genes during stomatal development.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1002292294 226 HSATEQRRRSKINDRFQLLRDLLPHN-DQKRDKASFLLEVIEYIRFLQEKVQKYE 279
Cdd:cd11448     3 HIAVERNRRKQMNEHLNVLRSLMPGSyIQRGDQASIVGGAIEFVKELEQLLQSLE 57

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in transcription factor E3 (TFE3) and similar proteins; TFE3, also termed Class E basic helix-loop-helix protein 33 (bHLHe33), is a bHLHzip transcription factor that is involved in B cell function. It specifically recognizes and binds E-box sequences (5'-CANNTG-3'). Its efficient DNA-binding requires dimerization with itself or with another MiT/TFE family member such as TFEB or MITF.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1002292294 223 RSKHSATEQRRRSKINDRFQLLRDLLPHN---DQKRDKASFLLEVIEYIRFLQEKVQK 277
Cdd:cd18928    12 KDNHNLIERRRRFNINDRIKELGTLIPKStdpEMRWNKGTILKASVDYIRKLQKEQQR 69

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in upstream stimulatory factors, USF1, USF2 and similar proteins; Upstream stimulatory factor 1 and 2 (USF-1 and USF-2) are members of bHLHzip transcription factor family. USFs are ubiquitously expressed and key regulators of a wide number of gene regulation networks, including the stress and immune responses, cell cycle and proliferation, lipid and glucid metabolism. USFs recruit chromatin remodeling enzymes and interact with co-activators and the members of the transcription pre-initiation complex. USFs interact with high affinity to E-box regulatory elements.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1002292294 226 HSATEQRRRSKINDRFQLLRDLLP-----HNDQKRDKASFLLEVIEYIRFLQEKVQK 277
Cdd:cd11396     2 HNEVERRRRDKINNWIVKLAKIVPdcekdNSKQGQSKGGILSKACDYIQELRSQNER 58

basic helix-loop-helix-orange (bHLH-O) domain found in HERP/HES-like family; The HERP/HES-like family includes bHLH-O transcriptional regulators that are related to the Drosophila hairy and Enhancer-of-split (HES) proteins. The HERP (HES-related repressor protein) subfamily proteins contain a basic helix-loop-helix (bHLH) domain with an invariant glycine residue in its basic region, an orange domain in the central region and YXXW sequence motif at its C-terminal region. Hairy and enhancer of split (HES)-related repressor protein (HERP) proteins (HEY1, HEY2 and HEYL) act as downstream effectors of Notch signaling. They are involved in cardiovascular development and have roles in somitogenesis, myogenesis and gliogenesis. Hairy and enhancer of split-related protein HELT is a transcriptional repressor expressed in the developing central nervous system. It binds preferentially to the canonical E box sequence 5'-CACGCG-3' and regulates neuronal differentiation and/or identity. Differentially expressed in chondrocytes proteins, DEC1 and DEC2, are widely expressed in both embryonic and adult tissues and have been implicated in apoptosis, cell proliferation, and circadian rhythms, as well as malignancy in various cancers. Drosophila melanogaster protein clockwork orange (Cwo) is also included in this subfamily. It is involved in the regulation of Drosophila circadian rhythms. It functions as both an activator and a repressor of clock gene expression. The HES subfamily proteins contain a basic helix-loop-helix (bHLH) domain with an invariant proline residue in its basic region, an orange domain in the central region and a conserved tetrapeptide motif, WRPW, at its C-terminal region. They form heterodimers or homodimers via their HLH domain and bind DNA to repress gene transcription that play an essential role in development of both compartment and boundary cells of the central nervous system.

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gi 1002292294 229 TEQRRRSKINDRFQLLRDLLPHNDQKRD-----KASFLLEVIEYIRFLQEKV 275
Cdd:cd19685     1 SEKRRRQRINDKLNQLKELLPPNLSKQSrsklsKAEILEMAITELRRLQQEV 52

basic helix-loop-helix-Per-ARNT-Sim (bHLH-PAS) domain family; bHLH-PAS domain has been found in a large group of bHLH transcription regulators that are involved in gene expression responding to environmental change and controlling aspects of neural development, including proteins from aryl hydrocarbon receptor nuclear translocator (ARNT) family, hypoxia-inducible factor (HIF) family, aryl hydrocarbon receptor (AhR) family, neuronal PAS domain-containing protein (NPAS) family, Circadian locomotor output cycles protein kaput (CLOCK)-like family, and single-minded (SIM) family. bHLH-PAS transcriptional regulatory factors have a bHLH DNA-binding domain followed by two PAS domains and a C-terminal activation or repression domain. bHLH-PAS family members can be divided into class I and class II based on their dimerization partner. bHLH-PAS class I factors include AhR, HIF and SIM. The best characterized bHLH-PAS Class II protein is the ubiquitous ARNT. Some members of bHLH-PAS family act as transcriptional coactivators (such as NCoA) that lack the ability to dimerize and bind DNA.

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gi 1002292294 223 RSKHSATEQRRRSKINDRFQLLRDLLPHN---DQKRDKASFLLEVIEYIRFLQ 272
Cdd:cd11391     1 REKSREAAKKRRDKENAEISELASLLPLPpavGSKLDKLSVLRLAVAYLRLKK 53

basic helix-loop-helix (bHLH) domain found in achaete-scute complex-like (ASCL) family; The achaete-scute complex-like (ASCL, also known as achaete-scute complex homolog or ASH) family of bHLH transcription factors, ASCL1-5, have been implicated in cell fate specification and differentiation. They are critical for proper development of the nervous system. The deregulation of ASCL plays a key role in psychiatric and neurological disorders. ASCL-1, also termed Class A basic helix-loop-helix protein 46 (bHLHa46), or achaete-scute homolog 1 (ASH-1), or mammalian achaete-scute homolog 1 (Mash1), is a neural-specific bHLH transcription factor that is expressed in subsets of neural progenitors in both the central and peripheral nervous system. It plays a key role in neuronal differentiation and specification in the nervous system. ASCL-2, also termed achaete-scute homolog 2 (ASH-2), or Class A basic helix-loop-helix protein 45 (bHLHa45), or mammalian achaete-scute homolog 2 (Mash2), is a bHLH transcription factor that is involved in Schwann cell differentiation and control of proliferation in adult peripheral nerves. ASCL-3, also termed Class A basic helix-loop-helix protein 42 (bHLHa42), or bHLH transcriptional regulator Sgn-1, or achaete-scute homolog 3 (ASH-3), is a bHLH transcription factor specifically localized in the duct cells of the salivary glands. It may act as transcriptional repressor that inhibits myogenesis. The family also includes Drosophila melanogaster achaete-scute complex (AS-C) proteins, which consists of lethal of scute (also known as achaete-scute complex protein T3 or AST3), scute (also known as achaete-scute complex protein T4 or AST4), achaete (also known as achaete-scute complex protein T5 or AST5), and asense (also known as achaete-scute complex protein T8 or AST8). They are involved in the determination of the neuronal precursors in the peripheral nervous system and the central nervous system, as well as in sex determination and dosage compensation.

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gi 1002292294 225 KHSATEQRRRSKINDRFQLLRDLLPH--NDQKRDKASFLLEVIEYIRFLQE 273
Cdd:cd11418     4 RRNERERRRVQAVNDAFDRLRQHVPYlkRRKKLSKVKTLRRAIEYIRHLQK 54

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in upstream stimulatory factor 2 (USF2) and similar proteins; USF2, also termed Class B basic helix-loop-helix protein 12 (bHLHb12), or major late transcription factor 2, or FOS-interacting protein (FIP), or upstream transcription factor 2, is a bHLHzip transcription factor that binds to a symmetrical DNA sequence (E-boxes) (5'-CACGTG-3') that is found in a variety of viral and cellular promoters.

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gi 1002292294 223 RSKHSATEQRRRSKINDRFQLLRDLLP--HNDQKRDKAS---FLLEVIEYIRFLQEKVQKYEVSYPE 284
Cdd:cd18923     9 RAQHNEVERRRRDKINNWIVQLSKIIPdcNTDNSKTGASkggILSKACDYIRELRQTNQRMQETYKE 75

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in MAX gene-associated protein (MGA) and similar proteins; MGA, also termed MAX dimerization protein 5 (MAD5), is a dual specificity T-box/ bHLHzip transcription factor that regulates the expression of both Max-network and T-box family target genes. It contains a Myc-like bHLHZip motif and requires heterodimerization with Max for binding to the preferred Myc-Max-binding site CACGTG. In addition to the bHLHZip domain, MGA harbors a second DNA-binding domain, the T-box or T-domain. It thus binds the preferred Brachyury-binding sequence and represses transcription of reporter genes containing promoter-proximal Brachyury-binding sites.

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gi 1002292294 223 RSKHSATEQRRRSKINDRFQLLRDLLP-HNDQKRDKASFLLEVIEYIRFLQEKVQK 277
Cdd:cd18911     1 RRTHTANERRRRNEMRDLFEKLKRTLGlHNLPKVSKYYILKQAFEEIQGLTDQADR 56

basic Helix-Loop-Helix-zipper (bHLHzip) domain found in MLX-interacting protein (MLXIP) and similar proteins; MLXIP, also termed Class E basic helix-loop-helix protein 36 (bHLHe36), or transcriptional activator MondoA, is a bHLHZip transcriptional activator that binds DNA as a heterodimer with Mlx. It binds to the canonical E box sequence 5'-CACGTG-3' and plays a role in transcriptional activation of glycolytic target genes. MLXIP is most highly expressed in skeletal muscle and functions as an indirect glucose sensor, by sensing glucose 6-phosphate and shuttling between the nucleus and the cytoplasm.

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gi 1002292294 223 RSKHSATEQRRRSKINDRFQLLRDLLPHNDQKR--DKASFLLEVIEYIRFLQ-EKVQKYE 279
Cdd:cd19688     4 RMKHISAEQKRRFNIKICFDTLNSLVSTLKNSKpiSNAITLQKTVEYIAKLQqERTQMQE 63