PprA contributes to Deinococcus radiodurans resistance to nalidixic acid, genome maintenance after DNA damage and interacts with deinococcal topoisomerases.
PprA is known to contribute to Deinococcus radiodurans' remarkable capacity to survive a variety of genotoxic assaults. The molecular bases for PprA's role(s) in the maintenance of the damaged D. radiodurans genome are incompletely understood, but PprA is thought to promote D. radiodurans's capacity for DSB repair. PprA is found in a multiprotein DNA processing complex along with an ATP type DNA ligase, and the D. radiodurans toposiomerase IB (DraTopoIB) as well as other proteins. Here, we show that PprA is a key contributor to D. radiodurans resistance to nalidixic acid (Nal), an inhibitor of topoisomerase II. Growth of wild type D. radiodurans and a pprA mutant were similar in the absence of exogenous genotoxic insults; however, the pprA mutant exhibited marked growth delay and a higher frequency of anucleate cells following treatment with DNA-damaging agents. We show that PprA interacts with both DraTopoIB and the Gyrase A subunit (DraGyrA) in vivo and that purified PprA enhances DraTopoIB catalysed relaxation of supercoiled DNA. Thus, besides promoting DNA repair, our findings suggest that PprA also contributes to preserving the integrity of the D. radiodurans genome following DNA damage by interacting with DNA topoisomerases and by facilitating the actions of DraTopoIB.
Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.
Swathi
S
Kota
Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India ; Division of Infectious Disease, Brigham and Women's Hospital, Department of Microbiology and Immunobiology, Harvard Medical School, and HHMI, Boston, Massachusetts, United States of America.
Vijaya K
VK
Charaka
Division of Infectious Disease, Brigham and Women's Hospital, Department of Microbiology and Immunobiology, Harvard Medical School, and HHMI, Boston, Massachusetts, United States of America.
Simon
S
Ringgaard
Division of Infectious Disease, Brigham and Women's Hospital, Department of Microbiology and Immunobiology, Harvard Medical School, and HHMI, Boston, Massachusetts, United States of America.
Matthew K
MK
Waldor
Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India ; Division of Infectious Disease, Brigham and Women's Hospital, Department of Microbiology and Immunobiology, Harvard Medical School, and HHMI, Boston, Massachusetts, United States of America.
Hari S
HS
Misra
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D004249:DNA Damage; D017931:DNA Primers; D004264:DNA Topoisomerases, Type I / Q000378:metabolism*; D034301:Deinococcus / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016680:Genome, Bacterial; D009268:Nalidixic Acid / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D017931:DNA Primers; D009268:Nalidixic Acid; D004264:DNA Topoisomerases, Type I