Ayora S, Stiege A C, Alonso J C
Centro Nacional de Biotechnología, CSIC, Universidad Autónoma de Madrid, Spain.
Mol Microbiol. 1997 Feb;23(4):639-47. doi: 10.1046/j.1365-2958.1997.2431611.x.
The Bacillus subtilis RecR protein is required for DNA repair and recombination in vivo. In its N-terminal portion, RecR possesses potential zinc-ligand structures associated with the multicysteine (C4) superfamily. The number and arrangement of the cysteine residues is suggestive of RecR being a zinc-finger protein. One of the four cysteines (Cys-60) has been replaced by a Ser (C60S) or an Ala (C60A) residue to generate the recR60 and recR601 genes, respectively. B. subtilis recR60, recR601 or delta recR1 (a null-mutant allele) cells are 10-, 134- and 144-fold more sensitive to 10 mM methanesulphonate and 95-, 900- and 1100-fold more sensitive to the lethal effect of 100 microM 4-nitroquinoline-1-oxide (4NQO) than the wild-type strain, respectively. The RecR zinc-ligand C4 motif does not seem to be accessible, because the protein is highly resistant to oxidation and moderately resistant to reduction. We have determined by different biochemical methods that RecR is a zinc metalloprotein whose cysteine residues have a structural and/or functional role.
枯草芽孢杆菌RecR蛋白在体内的DNA修复和重组过程中是必需的。在其N端部分，RecR具有与多半胱氨酸（C4）超家族相关的潜在锌配体结构。半胱氨酸残基的数量和排列表明RecR是一种锌指蛋白。四个半胱氨酸之一（Cys-60）已分别被丝氨酸（C60S）或丙氨酸（C60A）残基取代，以分别产生recR60和recR601基因。枯草芽孢杆菌recR60、recR601或delta recR1（一个无效突变等位基因）细胞对10 mM甲磺酸的敏感性分别比野生型菌株高10倍、134倍和144倍，对100 microM 4-硝基喹啉-1-氧化物（4NQO）的致死效应的敏感性分别比野生型菌株高95倍、900倍和1100倍。RecR锌配体C4基序似乎不易接近，因为该蛋白对氧化具有高度抗性，对还原具有中度抗性。我们通过不同的生化方法确定RecR是一种锌金属蛋白，其半胱氨酸残基具有结构和/或功能作用。
