title: The Borrelia burgdorferi telomere resolvase, ResT, anneals ssDNA complexed with its cognate ssDNA-binding protein.
abstract: Spirochetes of the genus Borrelia possess unusual genomes that consist in a linear chromosome and multiple linear and circular plasmids. The linear replicons are terminated by covalently closed hairpin ends, referred to as hairpin telomeres. The hairpin telomeres represent a simple solution to the end-replication problem. Deoxyribonucleic acid replication initiates internally and proceeds bidirectionally toward the hairpin telomeres. The telomere resolvase, ResT, forms the hairpin telomeres from replicated telomere intermediates in a reaction with similarities to those promoted by type IB topoisomerases and tyrosine recombinases. ResT has also been shown to possess DNA single-strand annealing activity. We report here that ResT promotes single-strand annealing of both free DNA strands and ssDNA complexed with single-stranded DNA binding protein (SSB). The annealing of complementary strands bound by SSB requires a ResT-SSB interaction that is mediated by the conserved amphipathic C-terminal tail of SSB. These properties of ResT are similar to those demonstrated for the recombination mediator protein, RecO, of the RecF pathway. Borrelia burgdorferi is unusual in lacking identifiable homologs of the RecFOR proteins. We propose that ResT may provide missing RecFOR functions.
authors.affiliation: Department of Microbiology and Immunology, College of Medicine, University of Saskatchewan Academic Health Sciences Building, 107 Wiggins Rd, Saskatoon, SK S7N 5E5, Canada.
authors.forename: Shu Hui
authors.initials: SH
authors.lastname: Huang
authors.affiliation: Department of Microbiology and Immunology, College of Medicine, University of Saskatchewan Academic Health Sciences Building, 107 Wiggins Rd, Saskatoon, SK S7N 5E5, Canada kerri.kobryn@usask.ca.
authors.forename: Kerri
authors.initials: K
authors.lastname: Kobryn
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D025065:Borrelia burgdorferi / Q000502:physiology*; D004269:DNA, Bacterial / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D004706:Endodeoxyribonucleases / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D004706:Endodeoxyribonucleases; C446515:ResT protein, Borrelia