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

CORREA EME; MARTINA MA; DE TULLIO L; ARGARAÑA CE; BARRA JL

ELSEVIER SCIENCE BV

Año: 2011 vol. 10 p. 1106 - 1106

uman 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