1gkj
From Proteopedia
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HISTIDINE AMMONIA-LYASE (HAL) MUTANT Y280F FROM PSEUDOMONAS PUTIDA
Overview
Histidine ammonia-lyase (EC 4.3.1.3) catalyzes the nonoxidative, elimination of the alpha-amino group of histidine using a, 4-methylidene-imidazole-5-one (MIO), which is formed autocatalytically, from the internal peptide segment 142Ala-Ser-Gly. The structure of the, enzyme inhibited by a reaction with l-cysteine was established at the very, high resolution of 1.0 A. Five active center mutants were produced and, their catalytic activities were measured. Among them, mutant Tyr280-->Phe, could be crystallized and its structure could be determined at 1.7 A, resolution. It contains a planar sp2-hybridized 144-N atom of MIO, in, contrast to the pyramidal sp3-hybridized 144-N of the wild-type. With the, planar 144-N atom, MIO assumes the conformation of a putative intermediate, aromatic ... [(full description)]
About this Structure
1GKJ is a [Single protein] structure of sequence from [Pseudomonas putida] with SO4 and GOL as [ligands]. Active as [[1]], with EC number [4.3.1.3]. Full crystallographic information is available from [OCA].
Reference
Structures of two histidine ammonia-lyase modifications and implications for the catalytic mechanism., Baedeker M, Schulz GE, Eur J Biochem. 2002 Mar;269(6):1790-7. PMID:11895450
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