The methionine sulfoxide reductases: Catalysis and substrate specificities
The methionine sulfoxide reductases: Catalysis and substrate specificities
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DOI：
10.1016/j.abb.2008.02.007
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发表时间：
2008-06-15
影响因子：
3.9
通讯作者：
Branlant, Guy
中科院分区：
文献类型：
--
作者：
Boschi-Muller, Sandrine;Gand, Adeline;Branlant, Guy
蛋白质中Met残基的氧化导致形成甲硫氨酸亚砜（MetSO）。甲硫氨酸亚砜还原酶（Methylsulfonesulfonate reductases，Msr）是一种广泛存在的酶，催化氧化的甲硫氨酸残基的亚砜功能的还原。在体内，Msrs的作用被描述为在保护细胞免受氧化损伤方面是必不可少的，并且在病原菌感染细胞中发挥作用。存在两种结构上不相关的Msrs，称为MsrA和MsrB，分别对亚砜功能的S和R异构体具有相反的立体选择性。这两个Msrs提出了类似的三步催化机制。第一步，称为还原酶步骤，导致在催化Cys上形成次磺酸，同时释放Met。近年来，已经做出了重大努力来表征参与催化的结构和分子因素，特别是还原酶步骤，以及结构特异性。(c)2008年爱思唯尔公司All rights reserved.
Oxidation of Met residues in proteins leads to the formation of methionine sulfoxides (MetSO). Methionine sulfoxide reductases (Msr) are ubiquitous enzymes, which catalyze the reduction of the sulfoxide function of the oxidized methionine residues. In vivo, the role of Msrs is described as essential in protecting cells against oxidative damages and to play a role in infection of cells by pathogenic bacteria. There exist two structurally-unrelated classes of Msrs, called MsrA and MsrB, with opposite stereoselectivity towards the S and R isomers of the sulfoxide function, respectively. Both Msrs present a similar three-step catalytic mechanism. The first step, called the reductase step, leads to the formation of a sulfenic acid on the catalytic Cys with the concomitant release of Met. In recent years, significant efforts have been made to characterize structural and molecular factors involved in the catalysis, in particular of the reductase step, and in structural specificities. (c) 2008 Elsevier Inc. All rights reserved.