The Borrelia burgdorferi telomere resolvase, ResT, possesses ATP-dependent DNA unwinding activity.
Spirochetes of the genus Borrelia possess unusual genomes harboring multiple linear and circular replicons. The linear replicons are terminated by covalently closed hairpin (hp) telomeres. Hairpin telomeres are formed from replicated intermediates by the telomere resolvase, ResT, in a phosphoryl transfer reaction with mechanistic similarities to those promoted by type 1B topoisomerases and tyrosine recombinases. There is growing evidence that ResT is multifunctional. Upon ResT depletion DNA replication unexpectedly ceases. Additionally, ResT possesses RecO-like biochemical activities being able to promote single-strand annealing on both free ssDNA and ssDNA complexed with cognate single-stranded DNA binding protein. We report here that ResT possesses DNA-dependent ATPase activity that promotes DNA unwinding with a 3΄-5΄ polarity. ResT can unwind a variety of substrates including synthetic replication forks and D-loops. We demonstrate that ResT's twin activities of DNA unwinding and annealing can drive regression of a model replication fork. These properties are similar to those of the RecQ helicase of the RecF pathway involved in DNA gap repair. We propose that ResT's combination of activities implicates it in replication and recombination processes operating on the linear chromosome and plasmids of Borrelia burgdorferi.
Department of Microbiology & Immunology, College of Medicine, University of Saskatchewan Academic Health Sciences Building, 107 Wiggins Rd, Saskatoon, SK, Canada
Shu Hui
SH
Huang
Department of Microbiology & Immunology, College of Medicine, University of Saskatchewan Academic Health Sciences Building, 107 Wiggins Rd, Saskatoon, SK, Canada
McKayla R
MR
Cozart
Department of Microbiology & Immunology, College of Medicine, University of Saskatchewan Academic Health Sciences Building, 107 Wiggins Rd, Saskatoon, SK, Canada
Madison A
MA
Hart
Department of Microbiology & Immunology, College of Medicine, University of Saskatchewan Academic Health Sciences Building, 107 Wiggins Rd, Saskatoon, SK, Canada
Kerri
K
Kobryn
D000255:Adenosine Triphosphate / Q000378:metabolism; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D025065:Borrelia burgdorferi / Q000235:genetics / Q000378:metabolism*; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D045522:Recombinases / Q000235:genetics / Q000378:metabolism*; D016615:Telomere / Q000378:metabolism
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011994:Recombinant Proteins; D045522:Recombinases; D000255:Adenosine Triphosphate; D004706:Endodeoxyribonucleases; C446515:ResT protein, Borrelia; D004265:DNA Helicases