Protein Family Models

KdsC family phosphatase such as 3-deoxy-manno-octulosonate-8-phosphatase KdsC, a HAD (haloacid dehalogenase) superfamily hydrolase that catalyzes the hydrolysis of 3-deoxy-D-manno-octulosonate 8-phosphate (KDO 8-P) to 3-deoxy-D-manno-octulosonate (KDO) and inorganic phosphate

Date:

2024-05-15

This family of proteins is a member of the IIIA subfamily of the haloacid dehalogenase (HAD) superfamily of hydrolases. All characterized members of this subfamily (TIGR01662) and most characterized members of the HAD superfamily are phosphatases. HAD superfamily phosphatases contain active site residues in several conserved catalytic motifs [1], all of which are found conserved here. One member of this family, the YrbI protein from H. influenzae has been cloned, expressed, purified and found to be an active 3-deoxy-D-manno-octulosonate 8-phosphate phosphatase[2]. Furthermore, its crystal structure has been determined [3]. This family consists of sequences from beta, gamma and epsilon proteobacteria, Aquifex, Fusobacterium, Porphyromonas and Methanosarcina. The Methanosarcina sequence is distinctive in that it is linked to an N-terminal cytidylyltransferase domain (PF02348) and is annotated as acylneuraminate cytidylyltransferase. This may give some clue as the function of these phosphatases. Several eukaryotic sequences scoring between trusted and noise are also closely related to this function such as the CMP-N-acetylneuraminic acid synthetase from mouse, but in these cases the phosphatase domain is clearly inactive as many of the active site residues are not conserved.

Date:

2021-04-27