Mycobacterial UvrD1 is a Ku-dependent DNA helicase that plays a role in multiple DNA repair events, including double-strand break repair.
Mycobacterium tuberculosis and other bacterial pathogens have a Ku-dependent nonhomologous end joining pathway of DNA double-strand break repair. Here we identify mycobacterial UvrD1 as a novel interaction partner for Ku in a genome-wide yeast two-hybrid screen. UvrD1 per se is a vigorous DNA-dependent ATPase but a feeble DNA helicase. Ku stimulates UvrD1 to catalyze ATP-dependent unwinding of 3'-tailed DNAs. UvrD1, Ku, and DNA form a stable ternary complex in the absence of ATP. The Ku binding determinants are located in the distinctive C-terminal segment of UvrD1. A second mycobacterial paralog, UvrD2, is a vigorous Ku-independent DNA helicase. Ablation of UvrD1 sensitizes Mycobacterium smegmatis to killing by ultraviolet and ionizing radiation and to a single chromosomal break generated by I-SceI endonuclease. The physical and functional interactions of bacterial Ku and UvrD1 highlight the potential for cross-talk between components of nonhomologous end joining and nucleotide excision repair pathways.
Sinha
Krishna Murari
KM
Molecular Biology, Sloan-Kettering Institute, Memorial-Sloan Kettering Cancer Center, New York, New York 10021, USA.
Stephanou
Nicolas C
NC
Gao
Feng
F
Glickman
Michael S
MS
Shuman
Stewart
S
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair / Q000502:physiology* / Q000528:radiation effects; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D005720:Gamma Rays; D020102:Mycobacterium smegmatis / Q000201:enzymology* / Q000235:genetics; D009169:Mycobacterium tuberculosis / Q000201:enzymology* / Q000235:genetics; D011485:Protein Binding / Q000502:physiology / Q000528:radiation effects; D017434:Protein Structure, Tertiary / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D029701:Saccharomyces cerevisiae Proteins; C037725:SCEI protein, S cerevisiae; D015252:Deoxyribonucleases, Type II Site-Specific; C573665:UvrD1 protein, Mycobacterium tuberculosis; D004265:DNA Helicases