Beetham J K, Grant D, Arand M, Garbarino J, Kiyosue T, Pinot F, Oesch F, Belknap W R, Shinozaki K, Hammock B D
Department of Entomology and Environmental Toxicology, University of California, Davis 95616.
DNA Cell Biol. 1995 Jan;14(1):61-71. doi: 10.1089/dna.1995.14.61.
We have analyzed amino acid sequence relationships among soluble and microsomal epoxide hydrolases, haloacid dehalogenases, and a haloalkane dehalogenase. The amino-terminal residues (1-229) of mammalian soluble epoxide hydrolase are homologous to a haloacid dehalogenase. The carboxy-terminal residues (230-554) of mammalian soluble epoxide hydrolase are homologous to haloalkane dehalogenase, to plant soluble epoxide hydrolase, and to microsomal epoxide hydrolase. The shared identity between the haloacid and haloalkane dehalogenases does not indicate relatedness between these two types of dehalogenases. The amino-terminal and carboxy-terminal homologies of mammalian soluble epoxide hydrolase to the respective dehalogenases suggests that this epoxide hydrolase, but not the soluble epoxide hydrolase of plant or the microsomal epoxide hydrolase, derives from a gene fusion. The homology of microsomal to soluble epoxide hydrolase suggests they derive from a gene duplication, probably of an ancestral bacterial (epoxide) hydrolase gene. Based on homology to haloalkane dehalogenase, the catalytic residues for the soluble and microsomal epoxide hydrolases are predicted. A nomenclature system based on divergent molecular evolution is proposed for these epoxide hydrolases.
我们分析了可溶性和微粒体环氧化物水解酶、卤代酸脱卤酶以及一种卤代烷脱卤酶之间的氨基酸序列关系。哺乳动物可溶性环氧化物水解酶的氨基末端残基（1 - 229）与一种卤代酸脱卤酶同源。哺乳动物可溶性环氧化物水解酶的羧基末端残基（230 - 554）与卤代烷脱卤酶、植物可溶性环氧化物水解酶以及微粒体环氧化物水解酶同源。卤代酸脱卤酶和卤代烷脱卤酶之间的共有同一性并不表明这两种脱卤酶之间存在相关性。哺乳动物可溶性环氧化物水解酶与各自脱卤酶的氨基末端和羧基末端同源性表明，这种环氧化物水解酶，而非植物可溶性环氧化物水解酶或微粒体环氧化物水解酶，源自基因融合。微粒体环氧化物水解酶与可溶性环氧化物水解酶的同源性表明它们源自基因复制，可能是一个祖先细菌（环氧化物）水解酶基因的复制。基于与卤代烷脱卤酶的同源性，预测了可溶性和微粒体环氧化物水解酶的催化残基。针对这些环氧化物水解酶，提出了一种基于分歧分子进化的命名系统。
