Crystal structure of CcdB, a topoisomerase poison from E-coli
Crystal structure of CcdB, a topoisomerase poison from E-coli
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DOI：
10.1006/jmbi.1998.2395
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发表时间：
1999-01-29
影响因子：
5.6
通讯作者：
Wyns, L
中科院分区：
文献类型：
--
作者：
Loris, R;Dao-Thi, MH;Wyns, L
CcdB的晶体结构，一种蛋白质，毒素大肠杆菌促旋酶，被确定为三种晶体形式。该蛋白质由一个五链反平行β折叠片层和一个C末端α螺旋组成。在片层的一个环中，插入了第二个小的三链反平行β片层，它作为翅膀伸出分子。该翼区含有受CcdA保护的LysC蛋白水解切割位点，因此形成可能的CcdA识别位点。二聚体通过折叠延伸和广泛的疏水接触形成，所述疏水接触涉及五个甲硫氨酸残基中的三个和α-螺旋的C末端。α-螺旋一侧的二聚体表面总体上带负电荷，而相对侧以及翼片主要是正电荷。我们建议，CcdB二聚体结合到GyrA的59 kDa的N-末端片段的中心孔，GyrA的头部二聚体接口中断后。(C)北京：科学出版社.
The crystal structure of CcdB, a protein that poisons Escherichia coli gyrase, was determined in three crystal forms. The protein;consists of a five-stranded antiparallel beta-pleated sheet followed by a C-terminal alpha-helix. In one of the loops of the sheet, a second small three-stranded antiparallel beta-sheet is inserted that sticks out of the molecule as a wing. This wing contains the LysC proteolytic cleavage site that is protected by CcdA and, therefore, forms a Likely CcdA recognition site. A dimer is formed by sheet extension and by extensive hydrophobic contacts involving three of the five methionine residues and the C terminus of the a-helix. The surface of the dimer on the side of the alpha-helix is overall negatively charged, while the opposite side as well as the wing sheet is dominated by positive charges. We propose that the CcdB dimer binds into the central hole of the 59 kDa N-terminal fragment of GyrA, after disruption of the head dimer interface of GyrA. (C) 1999 Academic Press.