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- ***************************************
- * L-lactate dehydrogenase active site *
- ***************************************
-
- L-lactate dehydrogenase (EC 1.1.1.27) (LDH) [1] catalyzes the final step in
- anaerobic glycolysis, the reduction of L-lactate to pyruvate. This tetrameric
- enzyme is present in prokaryotic and eukaryotic organisms. In vertebrates
- there are three isozymes of LDH: the M form (LDH-A), found predominantly in
- muscle tissues; the H form (LDH-B), found in heart muscle and the X form (LDH-
- C), found only in the spermatozoa of mammals and birds. In birds and
- crocodilian eye lenses, LDH-B serves as a structural protein and is known as
- epsilon-crystallin [2].
-
- L-2-hydroxyisocaproate dehydrogenase (EC 1.1.1.-) (L-hicDH) [3] catalyzes the
- reversible and stereospecific interconversion between 2-ketocarboxylic acids
- and L-2-hydroxy-carboxylic acids. L-hicDH is evolutionary related to LDH's.
-
- As a signature for LDH's we have selected a region that includes a conserved
- histidine which is essential to the catalytic mechanism.
-
- -Consensus pattern: [LIVMA]-G-[EQ]-H-G-[DN]-[ST]
- [H is the active site residue]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
- -Last update: May 1991 / Pattern and text revised.
-
- [ 1] Abad-Zapatero C., Griffith J.P., Sussman J.L., Rossmann M.G.
- J. Mol. Biol. 198:445-467(1987).
- [ 2] Hendriks W., Mulders J.W.M., Bibby M.A., Slingsby C., Bloemendal H.,
- de Jong W.W.
- Proc. Natl. Acad. Sci. U.S.A. 85:7114-7118(1988).
- [ 3] Lerch H.-P., Frank R., Collins J.
- Gene 83:263-270(1989).
-