Payton Mark, Mushtaq Adeel, Yu Tin-Wein, Wu Ling-Juan, Sinclair John, Sim Edith
Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK1.
Department of Chemistry, Box 351700, University of Washington, Seattle, WA 98195-1700, USA2.
Microbiology (Reading). 2001 May;147(Pt 5):1137-1147. doi: 10.1099/00221287-147-5-1137.
Arylamine N-acetyltransferases (NATs) are enzymes involved in the detoxification of a range of arylamine and hydrazine-based xenobiotics. NATs have been implicated in the endogenous metabolism of p-aminobenzoyl glutamate in eukaryotes, although very little is known about the distribution and function of NAT in the prokaryotic kingdom. Using DNA library screening techniques and the analysis of data from whole-genome sequencing projects, we have identified 18 nat-like sequences from the Proteobacteria and Firmicutes. Recently, the three-dimensional structure of NAT derived from the bacterium Salmonella typhimurium (PDB accession code 1E2T) was resolved and revealed an active site catalytic triad composed of Cys(69)-His(107)-Asp(122). These residues have been shown to be conserved in all prokaryotic and eukaryotic NAT homologues together with three highly conserved regions which are found proximal to the active site triad. The characterization of prokaryotic NATs and NAT-like enzymes is reported. It is also predicted that prokaryotic NATs, based on gene cluster composition and distribution amongst genomes, participate in the metabolism of xenobiotics derived from decomposition of organic materials.
芳胺N - 乙酰基转移酶（NATs）是一类参与多种基于芳胺和肼的外源性物质解毒过程的酶。NATs与真核生物中对氨基苯甲酰谷氨酸的内源性代谢有关，尽管对于原核生物界中NAT的分布和功能了解甚少。通过DNA文库筛选技术以及对全基因组测序项目数据的分析，我们从变形菌门和厚壁菌门中鉴定出了18个类nat序列。最近，源自鼠伤寒沙门氏菌的NAT的三维结构（蛋白质数据银行登录号1E2T）得到了解析，揭示了一个由半胱氨酸（69）-组氨酸（107）-天冬氨酸（122）组成的活性位点催化三联体。这些残基在所有原核和真核NAT同源物中都显示是保守的，同时在活性位点三联体附近还发现了三个高度保守的区域。本文报道了原核NATs和类NAT酶的特性。还预测，基于基因簇组成和在基因组中的分布，原核NATs参与源自有机物质分解的外源性物质的代谢。
