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- **********************************************
- * 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 the GDP-mannose which is a
- constituent of N- and O-linked glycans as well as GPI anchors. In prokaryotes
- is 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 comprise 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 to
- 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
- one in the C-terminal half. Both patterns contain a conserved histidine that
- could be involved in the binding of the zinc ion.
-
- -Consensus pattern: Y-x-D-x-N-H-K-P-E
- -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
- -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: June 1994 / First entry.
-
- [ 1] Proudfoot A.E.I., Turcatti G., Wells T.N.C., Payton M.A., Smith D.J.
- Eur. J. Biochem. 219:415-423(1994).
- [ 2] Coulin F., Magnenat E., Proudfoot A.E.I., Payton M.A., Scully P.,
- Wells T.N.C.
- Biochemistry 32:14139-14144(1993).
-