HMM Summary Page: TIGR01670

Function3-deoxy-D-manno-octulosonate 8-phosphate phosphatase, YrbI family
Trusted Cutoff106.95
Domain Trusted Cutoff106.95
Noise Cutoff52.85
Domain Noise Cutoff52.85
Isology Typesubfamily
EC Number3.1.3.45
HMM Length154
Mainrole CategoryCell envelope
Subrole CategoryBiosynthesis and degradation of surface polysaccharides and lipopolysaccharides
Gene Ontology TermGO:0009103: lipopolysaccharide biosynthetic process biological_process
GO:0019143: 3-deoxy-manno-octulosonate-8-phosphatase activity molecular_function
AuthorSelengut J
Entry DateSep 11 2002 11:10AM
Last ModifiedJan 23 2014 10:34AM
CommentThis 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.
ReferencesRN [1] RM PMID: 7966317 RT Computer analysis of bacterial haloacid dehalogenases defines a large superfamily of hydrolases with diverse specificity. Application of an iterative approach to database search. RA Koonin EV, Tatusov RL. RL J Mol Biol 1994 Nov 18;244(1):125-32 RN [2] RM PMID: 12639950 RT Escherichia coli YrbI is 3-deoxy-D-manno-octulosonate 8-phosphate phosphatase. RA Wu J, Woodard RW. RL J Biol Chem. 2003 May 16;278(20):18117-23. Epub 2003 Mar 14. RN [3] RM PMID: 11835514 RT From structure to function: YrbI from Haemophilus influenzae (HI1679) is a phosphatase. RA Parsons JF, Lim K, Tempczyk A, Krajewski W, Eisenstein E, Herzberg O. RL Proteins 2002 Mar 1;46(4):393-404
Genome PropertyGenProp0204: KDO(2)-lipid A (Re LPS) biosynthesis and delivery (HMM)