Solution structure of apo CopZ from Bacillus subtilis:: Further analysis of the changes associated with the presence of copper
Solution structure of apo CopZ from Bacillus subtilis:: Further analysis of the changes associated with the presence of copper
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DOI：
10.1021/bi0353326
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发表时间：
2003-11-25
期刊：
影响因子：
2.9
通讯作者：
Del Conte, R
中科院分区：
文献类型：
--
作者：
Banci, L;Bertini, I;Del Conte, R
测定了枯草芽孢杆菌apo CopZ的溶液结构，以研究金属结合时M-X-C-X-X-C铜(I)结合基序周围疏水相互作用的变化。该基序(CopZ中的Met 11)的蛋氨酸指向apo CopZ中的溶剂，而其硫原子与金属负载蛋白中的金属离子接近，尽管可能不在结合距离上。这种变化与Leu 37和Cys 16之间以载脂蛋白形式存在的相互作用的减弱以及Met 11和Tyr 65之间的相互作用的形成有关。环路1、3和5受金属绑定的影响。与其他同源蛋白质的结构比较证实，金属结合经常影响金属位点周围的疏水斑块，可能是为了优化和调节与伴侣的疏水相互作用。研究还表明，在核磁共振时间尺度上，apo-CopZ分子间的铜(I)交换较慢，而配对分子(如金属配位酮和金属泵)之间的这种交换较快。
The solution structure of apo CopZ from Bacillus subtilis has been determined with the aim of investigating the changes in the hydrophobic interactions around the M-X-C-X-X-C copper(I) binding motif upon metal binding. The methionine of this motif (Met 11 in CopZ) points toward the solvent in apo CopZ, whereas its sulfur atom is close to the metal ion in the metal-loaded protein, though probably not at binding distance. This change is associated with the weakening of the interaction between Leu 37 nd Cys 16, present in the apo form, and the formation of an interaction between Met 11 and Tyr 65. Loops 1, 3, and 5 are affected by metal binding. Comparison with the structure of other homologous proteins confirms that often metal binding affects a hydrophobic patch around the metal site, possibly for optimizing and tuning the hydrophobic interactions with the partners. It is also shown that copper(I) exchanges among apo CopZ molecules in slow exchange on the NMR time scale, whereas it is known that such exchange between partner molecules (i.e., metallochaperones and metal pumps) is fast.