毒素-抗毒素系统VapBC家族成员的结构及推测活性。来自结核分枝杆菌的VapBC-5。
Structure and proposed activity of a member of the VapBC family of toxin-antitoxin systems. VapBC-5 from Mycobacterium tuberculosis.
作者信息
Miallau Linda, Faller Michael, Chiang Janet, Arbing Mark, Guo Feng, Cascio Duilio, Eisenberg David
机构信息
UCLA-DOE Institute of Genomics and Proteomics, the Department of Biological Chemistry, David Geffen School of Medicine, Molecular Cell and Developmental Biology, and the Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1570.
UCLA-DOE Institute of Genomics and Proteomics, the Department of Biological Chemistry, David Geffen School of Medicine, Molecular Cell and Developmental Biology, and the Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1570; UCLA-DOE Institute of Genomics and Proteomics, the Department of Biological Chemistry, David Geffen School of Medicine, Molecular Cell and Developmental Biology, and the Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1570; UCLA-DOE Institute of Genomics and Proteomics, the Department of Biological Chemistry, David Geffen School of Medicine, Molecular Cell and Developmental Biology, and the Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1570.
出版信息
J Biol Chem. 2009 Jan 2;284(1):276-283. doi: 10.1074/jbc.M805061200. Epub 2008 Oct 24.
In prokaryotes, cognate toxin-antitoxin pairs have long been known, but no three-dimensional structure has been available for any given complex from Mycobacterium tuberculosis. Here we report the crystal structure and activity of a member of the VapBC family of complexes from M. tuberculosis. The toxin VapC-5 is a compact, 150 residues, two domain alpha/beta protein. Bent around the toxin is the VapB-5 antitoxin, a 33-residue alpha-helix. Assays suggest that the toxin is an Mg-enabled endoribonuclease, inhibited by the antitoxin. The lack of DNase activity is consistent with earlier suggestions that the complex represses its own operon. Furthermore, analysis of the interactions in the binding of the antitoxin to the toxin suggest that exquisite control is required to protect the bacteria cell from toxic VapC-5.
在原核生物中，同源毒素-抗毒素对早已为人所知，但结核分枝杆菌中任何特定复合物的三维结构都尚未获得。在此，我们报告了结核分枝杆菌VapBC复合物家族中一个成员的晶体结构和活性。毒素VapC-5是一种紧凑的、由150个残基组成的、具有两个结构域的α/β蛋白。围绕毒素弯曲的是VapB-5抗毒素，它是一个由33个残基组成的α螺旋。实验表明，该毒素是一种依赖镁的内切核糖核酸酶，可被抗毒素抑制。缺乏DNA酶活性与早期关于该复合物抑制其自身操纵子的观点一致。此外，对抗毒素与毒素结合过程中相互作用的分析表明，需要精确的调控来保护细菌细胞免受有毒的VapC-5的侵害。
Zotero 插件