biliverdin-producing heme oxygenase cleaves the heme ring at the alpha-methene bridge to form biliverdin, which is subsequently converted to bilirubin by biliverdin reductase
heme oxygenase; Heme oxygenase (HO, EC 1.14.14.18) catalyzes the rate limiting step in the ...
13-216
3.56e-100
heme oxygenase; Heme oxygenase (HO, EC 1.14.14.18) catalyzes the rate limiting step in the degradation of heme to biliverdin in a multi-step reaction. HO is essential for recycling iron from heme which is used as a substrate and cofactor for its own degradation to biliverdin, iron, and carbon monoxide. This family serves a variety of specific needs in different branches of life: in vertebrates, HO plays a role in heme homeostasis and oxidative stress response, and cellular signaling in mammals that include isoforms HO-1 and HO-2; in photosynthetic organisms including cyanobacteria, algae, and higher plants, biliverdin is used for photosynthetic pigment formation or light-sensing; and, in pathogenic bacteria, HO is part of a pathway for iron acquisition from host heme and heme products. HO shares tertiary structure similarity to methane monooxygenase (EC 1.14.13.25), ribonucleotide reductase (EC 1.17.4.1) and thiaminase II (EC 3.5.99.2), but shares little sequence homology.
Pssm-ID: 350855 Cd Length: 201 Bit Score: 291.84 E-value: 3.56e-100
heme oxygenase; Heme oxygenase (HO, EC 1.14.14.18) catalyzes the rate limiting step in the ...
13-216
3.56e-100
heme oxygenase; Heme oxygenase (HO, EC 1.14.14.18) catalyzes the rate limiting step in the degradation of heme to biliverdin in a multi-step reaction. HO is essential for recycling iron from heme which is used as a substrate and cofactor for its own degradation to biliverdin, iron, and carbon monoxide. This family serves a variety of specific needs in different branches of life: in vertebrates, HO plays a role in heme homeostasis and oxidative stress response, and cellular signaling in mammals that include isoforms HO-1 and HO-2; in photosynthetic organisms including cyanobacteria, algae, and higher plants, biliverdin is used for photosynthetic pigment formation or light-sensing; and, in pathogenic bacteria, HO is part of a pathway for iron acquisition from host heme and heme products. HO shares tertiary structure similarity to methane monooxygenase (EC 1.14.13.25), ribonucleotide reductase (EC 1.17.4.1) and thiaminase II (EC 3.5.99.2), but shares little sequence homology.
Pssm-ID: 350855 Cd Length: 201 Bit Score: 291.84 E-value: 3.56e-100
heme oxygenase in eukaryotes and some bacteria; This subfamily contains heme oxygenase (HO, EC ...
12-217
1.58e-88
heme oxygenase in eukaryotes and some bacteria; This subfamily contains heme oxygenase (HO, EC 1.14.14.18) found in eukaryotes as well as some proteobacteria, including cyanobacteria. Heme oxygenase (HO) catalyzes the rate limiting step in the degradation of heme to biliverdin in a multi-step reaction. HO is essential for recycling of iron from heme which is used as a substrate and cofactor for its own degradation to biliverdin, iron, and carbon monoxide. In vertebrates, HO plays a role in heme homeostasis and oxidative stress response, and cellular signaling in mammals that include isoforms HO-1, HO-2 and HO-3. HO-1 is ubiquitously expressed after induction while HO-2 expression is constitutive, mostly limited to certain organs, such as the brain, testes, and the vascular system. HO-3 is non-functional in humans, suggesting that the Hmox3 gene is a pseudogene derived from HO-2 transcripts. In higher plants and cyanobacteria, heme oxygenase is required for the synthesis of light-harvesting pigments, which contain tetrapyrrols derived from biliverdin. Candida albicans expresses a heme oxygenase that is required for the utilization of heme as a nutritional iron source, whereas Saccharomyces cerevisiae responds to iron deprivation by increasing Hmx1p transcription, which is controlled by the major iron-dependent transcription factor, Aft1p, and promotes both the re-utilization of heme iron and the regulation of heme-dependent transcription during periods of iron scarcity. In pathogenic bacteria, HO is part of a pathway for iron acquisition from host heme. In Leptospira interrogans, a pathogenic spirochete that causes leptospirosis, HO is required for iron utilization when hemoglobin is the sole iron source, thus making HO an interesting target for novel antimicrobial agents. HO shares tertiary structure similarity to methane monooxygenase (EC 1.14.13.25), ribonucleotide reductase (EC 1.17.4.1) and thiaminase II (EC 3.5.99.2), but shares little sequence homology.
Pssm-ID: 350856 Cd Length: 205 Bit Score: 262.14 E-value: 1.58e-88
heme oxygenase found in pathogenic bacteria; This subfamily contains bacterial heme oxygenase ...
13-216
5.25e-10
heme oxygenase found in pathogenic bacteria; This subfamily contains bacterial heme oxygenase (HO, EC 1.14.14.18), where HO is part of a pathway for iron acquisition from host heme and heme products. Most of these proteins have yet to be characterized. HO catalyzes the rate limiting step in the degradation of heme to biliverdin in a multi-step reaction. HO is essential for recycling of iron from heme which is used as a substrate and cofactor for its own degradation to biliverdin, iron, and carbon monoxide. This family includes heme oxygenase (pa-HO) from Pseudomonas aeruginosa, an opportunistic pathogen that causes a variety of systemic infections, particularly in those afflicted with cystic fibrosis, as well as cancer and AIDS patients who are immunosuppressed. Pa-HO, expressed by the PigA gene, is critical for the acquisition of host iron since there is essentially no free iron in mammals, and is unusual since it hydroxylates heme predominantly at the delta-meso heme carbon, while all other well-studied HOs hydroxylate the alpha-meso carbon. Also included in this family is Neisseria meningitidis HO which is substantially different from the human HO, with the reaction product being ferric biliverdin IXalpha rather than reduced iron and free biliverdin IXalpha. HO shares tertiary structure similarity to methane monooxygenase (EC 1.14.13.25), ribonucleotide reductase (EC 1.17.4.1) and thiaminase II (EC 3.5.99.2), but shares little sequence homology.
Pssm-ID: 350857 [Multi-domain] Cd Length: 182 Bit Score: 57.64 E-value: 5.25e-10
Database: CDSEARCH/cdd Low complexity filter: no Composition Based Adjustment: yes E-value threshold: 0.01
References:
Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
of the residues that compose this conserved feature have been mapped to the query sequence.
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of your query sequence and the protein sequences used to curate the domain model,
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The thumbnail image, if present, provides an approximate view of the feature's location in 3 dimensions.
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Functional characterization of the conserved domain architecture found on the query.
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This image shows a graphical summary of conserved domains identified on the query sequence.
The Show Concise/Full Display button at the top of the page can be used to select the desired level of detail: only top scoring hits
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Domains are color coded according to superfamilies
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Others (non-specific hits) and
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if a domain or superfamily has been annotated with functional sites (conserved features),
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click on the bars or triangles to view your query sequence embedded in a multiple sequence alignment of the proteins used to develop the corresponding domain model.
The table lists conserved domains identified on the query sequence. Click on the plus sign (+) on the left to display full descriptions, alignments, and scores.
Click on the domain model's accession number to view the multiple sequence alignment of the proteins used to develop the corresponding domain model.
To view your query sequence embedded in that multiple sequence alignment, click on the colored bars in the Graphical Summary portion of the search results page,
or click on the triangles, if present, that represent functional sites (conserved features)
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Concise Display shows only the best scoring domain model, in each hit category listed below except non-specific hits, for each region on the query sequence.
(labeled illustration) Standard Display shows only the best scoring domain model from each source, in each hit category listed below for each region on the query sequence.
(labeled illustration) Full Display shows all domain models, in each hit category below, that meet or exceed the RPS-BLAST threshold for statistical significance.
(labeled illustration) Four types of hits can be shown, as available,
for each region on the query sequence:
specific hits meet or exceed a domain-specific e-value threshold
(illustrated example)
and represent a very high confidence that the query sequence belongs to the same protein family as the sequences use to create the domain model
non-specific hits
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the domain superfamily to which the specific and non-specific hits belong
multi-domain models that were computationally detected and are likely to contain multiple single domains
Retrieve proteins that contain one or more of the domains present in the query sequence, using the Conserved Domain Architecture Retrieval Tool
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