Methylaspartate ammonia-lyase

methylaspartate ammonia-lyase
X-ray structure of methylaspartate ammonia lyase. PDB entry 1kko​[1]
Identifiers
EC number	4.3.1.2
CAS number	9033-26-5
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / EGO
Search PMC articles PubMed articles NCBI proteins

In enzymology, a methylaspartate ammonia-lyase (EC 4.3.1.2) is an enzyme that catalyzes the chemical reaction

L-threo-3-methylaspartate $\rightleftharpoons$ mesaconate + NH₃

Hence, this enzyme has one substrate, L-threo-3-methylaspartate, and two products, mesaconate and NH₃.

This enzyme belongs to the family of lyases, specifically ammonia lyases, which cleave carbon-nitrogen bonds. The systematic name of this enzyme class is L-threo-3-methylaspartate ammonia-lyase (mesaconate-forming). Other names in common use include beta-methylaspartase, 3-methylaspartase, and L-threo-3-methylaspartate ammonia-lyase. This enzyme participates in c5-branched dibasic acid metabolism and nitrogen metabolism. It employs one cofactor, cobamide.

Structural studies

Several structures of this enzyme have been deposited in the Protein Data Bank (linked in the infobox) which show it possesses a TIM barrel domain.

References

1. Levy, C. W.; Buckley, P. A.; Sedelnikova, S.; Kato, Y.; Asano, Y.; Rice, D. W.; Baker, P. J. (2002). "Insights into Enzyme Evolution Revealed by the Structure of Methylaspartate Ammonia Lyase". Structure 10 (1): 105–13. doi:10.1016/S0969-2126(01)00696-7. PMID 11796115.

• BARKER HA, SMYTH RD, WAWSZKIEWICZ EJ, LEE MN, WILSON RM (1958). "Enzymic preparation and characterization of an alpha-L-beta-methylaspartic acid". Arch. Biochem. Biophys. 78 (2): 468–76. doi:10.1016/0003-9861(58)90371-0. PMID 13618029.
• Bright HJ and Ingraham LL (1960). "The preparation of crystalline beta-methylaspartase". Biochim. Biophys. Acta 44: 586–588. doi:10.1016/0006-3002(60)91612-7.