{PDOC00746} {PS00965; PMI_I_1} {PS00966; PMI_I_2} {BEGIN} ********************************************** * Phosphomannose isomerase type I signatures * ********************************************** Phosphomannose isomerase (EC 5.3.1.8) (PMI) [1,2] is the enzyme that catalyzes the interconversion of mannose-6-phosphate and fructose-6-phosphate. In eukaryotes, it is involved in the synthesis of GDP-mannose which is a constituent of N- and O-linked glycans as well as GPI anchors. In prokaryotes, it is involved in a variety of pathways including capsular polysaccharide biosynthesis and D-mannose metabolism. Three classes of PMI have been defined on the basis of sequence similarities [1]. The first class comprises all known eukaryotic PMI as well as the enzyme encoded by the manA gene in enterobacteria such as Escherichia coli. Class I PMI's are proteins of about 42 to 50 Kd which bind a zinc ion essential for their activity. As signature patterns for class I PMI, we selected two conserved regions. The first one is located in the N-terminal section of these proteins, the second in the C-terminal half. Both patterns contain a residue involved [3] in the binding of the zinc ion. -Consensus pattern: Y-x-D-x-N-H-K-P-E [E is a zinc ligand] -Sequences known to belong to this class detected by the pattern: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Consensus pattern: H-A-Y-[LIVM]-x-G-x(2)-[LIVM]-E-x-M-A-x-S-D-N-x-[LIVM]-R-A- G-x-T-P-K [H is a zinc ligand] -Sequences known to belong to this class detected by the pattern: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Expert(s) to contact by email: Proudfoot A.E.I.; aep6830@ggr.co.uk -Last update: November 1997 / Text revised. [ 1] Proudfoot A.E.I., Turcatti G., Wells T.N., Payton M.A., Smith D.J. "Purification, cDNA cloning and heterologous expression of human phosphomannose isomerase." Eur. J. Biochem. 219:415-423(1994). PubMed=8307007 [ 2] Coulin F., Magnenat E., Proudfoot A.E.I., Payton M.A., Scully P., Wells T.N.C. "Identification of Cys-150 in the active site of phosphomannose isomerase from Candida albicans." Biochemistry 32:14139-14144(1993). PubMed=8260497 [ 3] Cleasby A., Wonacott A., Skarzynski T., Hubbard R.E., Davies G.J., Proudfoot A.E.I., Bernard A.R., Payton M.A., Wells T.N.C. "The x-ray crystal structure of phosphomannose isomerase from Candida albicans at 1.7 angstrom resolution." Nat. Struct. Biol. 3:470-479(1996). PubMed=8612079 -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}