1EF8

CRYSTAL STRUCTURE OF METHYLMALONYL COA DECARBOXYLASE

1EF8 の概要

• エントリーDOI: 10.2210/pdb1ef8/pdb
• 関連するPDBエントリー: 1EF9
• 分子名称: METHYLMALONYL COA DECARBOXYLASE, NICKEL (II) ION (3 entities in total)
• 機能のキーワード: methylmalonyl coa, decarboxylase, lyase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 87678.38

構造登録者

Benning, M.M.,Haller, T.,Gerlt, J.A.,Holden, H.M. (登録日: 2000-02-07, 公開日: 2000-05-24, 最終更新日: 2024-02-07)

主引用文献

Benning, M.M.,Haller, T.,Gerlt, J.A.,Holden, H.M.
New reactions in the crotonase superfamily: structure of methylmalonyl CoA decarboxylase from Escherichia coli.
Biochemistry, 39:4630-4639, 2000

PubMed Abstract: The molecular structure of methylmalonyl CoA decarboxylase (MMCD), a newly defined member of the crotonase superfamily encoded by the Escherichia coli genome, has been solved by X-ray crystallographic analyses to a resolution of 1.85 A for the unliganded form and to a resolution of 2.7 A for a complex with an inert thioether analogue of methylmalonyl CoA. Like two other structurally characterized members of the crotonase superfamily (crotonase and dienoyl CoA isomerase), MMCD is a hexamer (dimer of trimers) with each polypeptide chain composed of two structural motifs. The larger N-terminal domain contains the active site while the smaller C-terminal motif is alpha-helical and involved primarily in trimerization. Unlike the other members of the crotonase superfamily, however, the C-terminal motif is folded back onto the N-terminal domain such that each active site is wholly contained within a single subunit. The carboxylate group of the thioether analogue of methylmalonyl CoA is hydrogen bonded to the peptidic NH group of Gly 110 and the imidazole ring of His 66. From modeling studies, it appears that Tyr 140 is positioned within the active site to participate in the decarboxylation reaction by orienting the carboxylate group of methylmalonyl CoA so that it is orthogonal to the plane of the thioester carbonyl group. Surprisingly, while the active site of MMCD contains Glu 113, which is homologous to the general acid/base Glu 144 in the active site of crotonase, its carboxylate side chain is hydrogen bonded to Arg 86, suggesting that it is not directly involved in catalysis. The new constellation of putative functional groups observed in the active site of MMCD underscores the diversity of function in this superfamily.

PubMed: 10769118
DOI: 10.1021/bi9928896

実験手法

X-RAY DIFFRACTION (1.85 Å)