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- *****************************************************
- * Phosphoenolpyruvate carboxykinase (GTP) signature *
- *****************************************************
-
- Phosphoenolpyruvate carboxykinase (GTP) (EC 4.1.1.32) (PEPCK) [1] catalyzes
- the formation of phosphoenolpyruvate by decarboxylation of oxaloacetate while
- hydrolyzing GTP, a rate limiting step in gluconeogenesis (the biosynthesis of
- glucose). In vertebrates there are two isozymes: a cytosolic form whose
- activity is affected by hormones regulating this metabolic process (such as
- glucagon, or insulin) and a mitochondrial form.
-
- An essential cysteine residue has been proposed [2] to be implicated in the
- catalytic mechanism; this residue is located in the central part of PEPCK and
- is in the center of a perfectly conserved region that we use as a signature
- pattern.
-
- -Consensus pattern: F-P-S-A-C-G-K-T-N
- [C is the putative active site residue]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Note: phosphoenolpyruvate carboxykinase (ATP) (EC 4.1.1.49) an enzyme that
- catalyzes the same reaction, but using ATP instead of GTP, is not related to
- the above enzyme (see the relevant section).
-
- -Last update: December 1991 / Text revised.
-
- [ 1] Weldon S.L., Rando A., Matathias A.S., Hod Y., Kalonick P.A., Savon S.,
- Cook J.S., Hanson R.W.
- J. Biol. Chem. 265:7308-7317(1990).
- [ 2] Lewis C.T., Seyer J.M., Carlson G.M.
- J. Biol. Chem. 264:27-33(1989).
-