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- **************************************
- * Methylmalonyl-CoA mutase signature *
- **************************************
-
- Methylmalonyl-CoA mutase (EC 5.4.99.2) (MCM) [1] is an adenosylcobalamin
- (vitamin B12) dependent enzyme that catalyzes the isomerization between
- methylmalonyl-CoA and succinyl-CoA. MCM is involved in various catabolic or
- biosynthetic pathways; for example in man it is involved in the degradation of
- several amino acids, odd-chain fatty acids and cholesterol via propionyl-CoA
- to the tricarboxylic acid cycle; while in some bacteria it is involved in the
- synthesis of propionate from tricarboxylic acid-cycle intermediates.
-
- Deficiency of MCM in man causes an often fatal disorder of organic acid
- metabolism termed methylmalonic acidemia.
-
- In eukaryotes MCM is located in the mitochondrial matrix and is a homodimer of
- a polypeptide chain of about 710 amino acids. In bacteria MCM is a dimer of
- two non-identical, yet structurally related chains.
-
- The sequences of eukaryotic and prokaryotic MCM are rather well conserved.
- This family also includes an Escherichia coli protein (gene sbm) whose
- function is not yet known.
-
- As a signature pattern we selected the best conserved region which is located
- in the central part of these sequences.
-
- -Consensus pattern: R-I-A-R-N-T-x(2)-[LIVMF](2)-x-[EQ]-E-x(4)-[KR]-x(2)-D-P-x-
- [GSA]-G-S
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Note: a small degree of similarity is said [2] to exist between MCM and the
- large subunit of the adenosylcobalamin-dependent enzyme ethanolamine ammonia-
- lyase, but this similarity is so weak that these two type of enzymes can not
- be detected by a single pattern.
-
- -Last update: June 1994 / Pattern and text revised.
-
- [ 1] Ledley F.D.
- BioEssays 12:335-340(1990).
- [ 2] Faust L.R.P., Connor J.A., Roof D.M., Hoch J.A., Babior B.M.
- J. Biol. Chem. 265:12462-12466(1990).
-