title: Functional analysis of the interaction between the mismatch repair protein MutS and the replication processivity factor β clamp in Pseudomonas aeruginosa.
abstract: Interaction between MutS and the replication factor β clamp has been extensively studied in a Mismatch Repair context; however, its functional consequences are not well understood. We have analyzed the role of the MutS-β clamp interaction in Pseudomonas aeruginosa by characterizing a β clamp binding motif mutant, denominated MutSβ, which does not interact with the replication factor. A detailed characterization of P. aeruginosa strain PAO1 harboring a chromosomal mutSβ allele demonstrated that this mutant strain exhibited mutation rates to rifampicin and ciprofloxacin resistance comparable to that of the parental strain. mutSβ PAO1 was as proficient as the parental strain for DNA repair under highly mutagenic conditions imposed by the adenine base analog 2-aminopurine. In addition, using a tetracycline resistance reversion assay to assess the repair of a frameshift mutation, we determined that the parental and mutSβ strains exhibited similar reversion rates. Our results clearly indicate that the MutS-β clamp interaction does not have a central role in the methylation-independent Mismatch Repair of P. aeruginosa.
authors.affiliation: Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina. mmonti@mail.fcq.unc.edu.ar
authors.forename: Mariela R
authors.initials: MR
authors.lastname: Monti
authors.forename: Virginia
authors.initials: V
authors.lastname: Miguel
authors.forename: Maria V
authors.initials: MV
authors.lastname: Borgogno
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Argaraña
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D004258:DNA Polymerase III / Q000235:genetics / Q000378:metabolism*; D051719:MutS DNA Mismatch-Binding Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D059645:Mutation Rate; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism*
chemical_list: C101139:beta subunit, DNA polymerase III; D004258:DNA Polymerase III; D051719:MutS DNA Mismatch-Binding Protein