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- *****************************************
- * Pyruvate kinase active site signature *
- *****************************************
-
- Pyruvate kinase (EC 2.7.1.40) (PK) [1] catalyzes the final step in glycolysis,
- the conversion of phosphoenolpyruvate to pyruvate with the concomitant
- phosphorylation of ADP to ATP. PK requires both magnesium and potassium ions
- for its activity. PK is found in all living organisms. In vertebrates there
- are four, tissues specific, isozymes: L (liver), R (red cells), M1 (muscle,
- heart, and brain), and M2 (early fetal tissues). In Escherichia coli there are
- two isozymes: PK-I (gene pykF) and PK-II (gene pykA). All PK isozymes seem to
- be tetramers of identical subunits of about 500 amino acid residues.
-
- As a signature pattern for PK we selected a conserved region that includes a
- lysine residue which seems to be the acid/base catalyst responsible for the
- interconversion of pyruvate and enolpyruvate, and a glutamic acid residue
- implicated in the binding of the magnesium ion.
-
- -Consensus pattern: [LIVM](2)-x-K-[LIVM]-E-[NR]-x-[EQ]-[GA]
- [K is the active site residue]
- [E is a magnesium ligand]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
- -Last update: December 1991 / Pattern and text revised.
-
- [ 1] Muirhead H.
- Biochem. Soc. Trans. 18:193-196(1990).
-