Some amino acids of the Pseudomonas aeruginosa MutL D(Q/M)HA(X)2E(X)4E conserved motif are essential for the in vivo function of the protein but not for the in vitro endonuclease activity
Some amino acids of the Pseudomonas aeruginosa MutL D(Q/M)HA(X)2E(X)4E conserved motif are essential for the in vivo function of the protein but not for the in vitro endonuclease activity
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DOI：
10.1016/j.dnarep.2011.08.007
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发表时间：
2011-11-10
期刊：
影响因子：
3.8
通讯作者：
Barra, Jose L.
中科院分区：
文献类型：
--
作者：
Correa, Elisa M. E.;Martina, Mariana A.;Barra, Jose L.
人和酿酒酵母MutLα以及一些细菌MutL蛋白具有依赖于金属离子的内切酶活性，这对这些蛋白的体内功能是重要的。人类PMS2、酿酒酵母PMS1和一些细菌MutL蛋白C-末端的保守氨基酸与金属结合/核酸内切酶活性有关。然而，单个氨基酸对这些活性的贡献还没有完全阐明。在这项工作中，我们证明了铜绿假单胞菌MutL蛋白在体外具有金属离子依赖的核酸内切酶活性。与以前发表的结果一致，我们观察到天冬氨酸、保守的C-末端DMHAHERITYE区域的第一个组氨酸或第一个谷氨酸的突变导致体内蛋白质的无功能。我们还确定精氨酸残基对该蛋白的体内功能是必不可少的。然而，我们出乎意料地观察到，第一个谷氨酸突变体衍生物虽然在体内没有功能，但其体外内切酶活性甚至高于野生型蛋白。(C)2011爱思唯尔B.V.保留所有权利。
Human and Saccharomyces cerevisiae MutL alpha., and some bacterial MutL proteins, possess a metal ion-dependent endonuclease activity which is important for the in vivo function of these proteins. Conserved amino acids of the C-terminal region of human PMS2, S. cerevisiae PMS1 and of some bacterial MutL proteins have been implicated in the metal-binding/endonuclease activity. However, the contribution of individual amino acids to these activities has not yet been fully elucidated. In this work we show that Pseudomonas aeruginosa MutL protein possess an in vitro metal ion-dependent endonuclease activity. In agreement with previous published results, we observed that mutation of the aspartic acid, the first histidine or the first glutamic acid of the conserved C-terminal DMHAAHERITYE region results in nonfunctional in vivo proteins. We also determined that the arginine residue is essential for the in vivo function of this protein. However, we unexpectedly observed that although the first glutamic acid mutant derivative is not functional in vivo, its in vitro endonuclease activity is even higher than that of the wild-type protein. (C) 2011 Elsevier B.V. All rights reserved.