INVESTIGADORES
MIGUEL Virginia
artículos
Título:
Analysis of the Interaction Interfaces of the N-Terminal Domain from Pseudomonas aeruginosa MutL
Autor/es:
MIGUEL V; CORREA EME; DE TULLIO L; BARRA JL; ARGARAÑA CE; VILLARREAL MA
Revista:
PLOS ONE
Editorial:
PUBLIC LIBRARY SCIENCE
Referencias:
Lugar: San Francisco; Año: 2013 vol. 8 p. 69907 - 69907
ISSN:
1932-6203
Resumen:
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.