INVESTIGADORES
BARRA Jose Luis
artículos
Título:
Analysis of the interaction interfaces of the N-terminal domain from Pseudomonas aeruginosa MutL
Autor/es:
MIGUEL, V.; CORREA, E. M. E.; DE TULLIO, L.; BARRA, J. L.; ARGARAÑA, C. E.; VILLAREAL, M. A.
Revista:
PLOS ONE
Editorial:
PUBLIC LIBRARY SCIENCE
Referencias:
Lugar: San Francisco; Año: 2013 p. 1 - 13
ISSN:
1932-6203
Resumen:
Abstract
Mismatch Repair System corrects mutations arising from DNA replication that escape from DNA polymerase proofreading
activity. This system consists of three main proteins, MutS-L-H, responsible for lesion recognition and repair. MutL is a
member of GHKL ATPase family and its ATPase cycle has been proposed to modulate MutL activity during the repair
process. Pseudomonas aeruginosa MutL (PaMutL) contains an N-terminal (NTD) ATPase domain connected by a linker to a Cterminal
(CTD) dimerization domain that possesses metal ion-dependent endonuclease activity. With the aim to identify
characteristics that allow the PaMutL NTD allosteric control of CTD endonuclease activity, we used an in silico and
experimental approach to determine the interaction surfaces of P. aeruginosa NTD (PaNTD), and compared it with the well
characterized Escherichia coli MutL NTD (EcNTD). Molecular dynamics simulations of PaNTD and EcNTD bound to or free of
adenosine nucleotides showed that a significant difference exists between the behavior of the EcNTD and PaNTD
dimerization interface, particularly in the ATP lid. Structure based simulations of MutL homologues with endonuclease
activity were performed that allowed an insight of the dimerization interface behavior in this family of proteins. Our
experimental results show that, unlike EcNTD, PaNTD is dimeric in presence of ADP. Simulations in mixed solvent allowed us
to identify the PaNTD putative DNA binding patch and a putative interaction patch located opposite to the dimerization
face. Structure based simulations of PaNTD dimer in presence of ADP or ATP suggest that nucleotide binding could
differentially modulate PaNTD protein-protein interactions. Far western assays performed in presence of ADP or ATP are in
agreement with our in silico analysis.