1kko
From Proteopedia
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CRYSTAL STRUCTURE OF CITROBACTER AMALONATICUS METHYLASPARTATE AMMONIA LYASE
Overview
Methylaspartate ammonia lyase (MAL) catalyzes the magnesium-dependent reversible alpha,beta-elimination of ammonia from L-threo-(2S,3S)-3-methylaspartic acid to mesaconic acid. The 1.3 A MAD crystal structure of the dimeric Citrobacter amalonaticus MAL shows that each subunit comprises two domains, one of which adopts the classical TIM barrel fold, with the active site at the C-terminal end of the barrel. Despite very low sequence similarity, the structure of MAL is closely related to those of representative members of the enolase superfamily, indicating that the mechanism of MAL involves the initial abstraction of a proton alpha to the 3-carboxyl of (2S,3S)-3-methylasparic acid to yield an enolic intermediate. This analysis resolves the conflict that had linked MAL to the histidine and phenylalanine ammonia lyase family of enzymes.
About this Structure
1KKO is a Single protein structure of sequence from Citrobacter amalonaticus with as ligand. Active as Methylaspartate ammonia-lyase, with EC number 4.3.1.2 Full crystallographic information is available from OCA.
Reference
Insights into enzyme evolution revealed by the structure of methylaspartate ammonia lyase., Levy CW, Buckley PA, Sedelnikova S, Kato Y, Asano Y, Rice DW, Baker PJ, Structure. 2002 Jan;10(1):105-13. PMID:11796115
Page seeded by OCA on Thu Feb 21 13:35:11 2008
