|PROSITE documentation PDOC00101 [for PROSITE entry PS00110]|
Pyruvate kinase (EC 18.104.22.168) (PK)  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.Last update:
July 1999 / Pattern and text revised.
PROSITE method (with tools and information) covered by this documentation:
|Title||Isoenzymes of pyruvate kinase.|
|Source||Biochem. Soc. Trans. 18:193-196(1990).|