Analysis of protein-protein/protein-DNA interfaces of Pseudomonas aeruginosa MutL N-terminal

VIRGINIA MIGUEL; ELISA M. E. CORREA; LUISINA DE TULLIO; JOSÉ LUIS BARRA; CARLOS E. ARGARAÑA; MARCOS A. VILLAREAL

Potrero de los Funes. San Luis

Congreso; XLVII Reunión Anual. Sociedad Argentina de Investigación en; 2011

SAIB

Mismatch Repair System (MRS) corrects mutations arising from DNA replication that escape from DNA polymerase proofreading activity. MutL is a member of GHL ATPase family and the ATPase cycle has been proposed to modulate MutL´s activity during the repair process. Pseudomonas aeruginosa MutL contains an N-terminal (NTD) ATPase domain connected by a linker to a C-terminal (CTD) dimerization domain that possesses a metal ion-dependent endonuclease activity. With the aim to identify characteristics that allow the NTD allosteric control of CTD endonuclease activity, we used a practical and in-silico approach to determine interaction surfaces of P. aeruginosa NTD (paNTD). Unlike E. coli NTD (ecNTD), paNTD is dimeric in absence of nucleotide. MD simulations of paNTD models and ecNTD with or without ATP showed that a significant difference exists in the behavior of the ecNTD and paNTD ATP lid. Also, simulations in mixed solvent, along with in vitro assays, allowed us to identify paNTD putative DNA binding patch, determined that DNA binding is nucleotide modulated and to identify a putative interaction patch located opposite to the dimerization face that is capable of mediating protein-protein interactions.