4QLX

Crystal structure of CLA-ER with product binding

4QLX の概要

• エントリーDOI: 10.2210/pdb4qlx/pdb
• 関連するPDBエントリー: 4QLY
• 分子名称: Nitroreductase family protein, FLAVIN MONONUCLEOTIDE, 10-oxooctadecanoic acid, ... (5 entities in total)
• 機能のキーワード: nadh oxidase/flavin reductase family, enone reductase, ketoc, fmn, oxidoreductase
• 由来する生物種: Lactobacillus plantarum
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 50588.51

構造登録者

Hou, F.,Miyakawa, T.,Tanokura, M. (登録日: 2014-06-13, 公開日: 2015-02-25, 最終更新日: 2023-11-08)

主引用文献

Hou, F.,Miyakawa, T.,Kitamura, N.,Takeuchi, M.,Park, S.B.,Kishino, S.,Ogawa, J.,Tanokura, M.
Structure and reaction mechanism of a novel enone reductase.
Febs J., 282:1526-1537, 2015

PubMed Abstract: Recently, a novel gut-bacterial fatty acid metabolism, saturation of polyunsaturated fatty acid, that modifies fatty acid composition of the host and is expected to improve our health by altering lipid metabolism related to the onset of metabolic syndrome, was discovered in Lactobacillus plantarum AKU 1009a. Enzymes constituting the pathway catalyze sequential reactions of free fatty acids without CoA or acyl carrier protein. Among these enzymes, CLA-ER was identified as an enone reductase that can saturate the C=C bond in the 10-oxo-trans-11-octadecenoic acid (KetoB) to produce 10-oxo-octadecanoic acid (KetoC). This enzyme is the sole member of the NADH oxidase/flavin reductase family that has been identified to exert an enone reduction activity. Here, we report both the structure of holo CLA-ER with cofactor FMN and the KetoC-bound structure, which elucidate the structural basis of enone group recognition of free fatty acids and provide the unique catalytic mechanism as an enone reductase in the NADH oxidase/flavin reductase family. A 'cap' structure of CLA-ER underwent a large conformational change upon KetoC binding. The resulting binding site adopts a sandglass shape and is positively charged at one side, which is suitable to recognize a fatty acid molecule with enone group. Based on the crystal structures and enzymatic activities of several mutants, we identified C51, F126 and Y101 as the critical residues for the reaction and proposed an alternative electron transfer pathway of CLA-ER. These findings expand our understanding of the complexity of fatty acid metabolism.

PubMed: 25702712
DOI: 10.1111/febs.13239

実験手法

X-RAY DIFFRACTION (1.95 Å)