The telomere resolvase of the Lyme disease spirochete, Borrelia burgdorferi, promotes DNA single-strand annealing and strand exchange.
Spirochetes of the genus Borrelia include the tick-transmitted causative agents of Lyme disease and relapsing fever. They possess unusual genomes composed mainly of linear replicons terminated by closed DNA hairpin telomeres. Hairpin telomeres present an uninterrupted DNA chain to the replication machinery overcoming the 'end-replication problem' for the linear replicons. Hairpin telomeres are formed from inverted repeat replicated telomere junctions by the telomere resolvase, ResT. ResT uses a reaction mechanism similar to that of the type IB topoisomerases and tyrosine recombinases. We report here that ResT also possesses single-strand annealing activity and a limited ability to promote DNA strand exchange reactions on partial duplex substrates. This combination of activities suggests ResT is a nexus between the seemingly distinct processes of telomere resolution and homologous recombination. Implications for hairpin telomere replication and linear plasmid recombination, including antigenic variation, are discussed.
Department of Microbiology and Immunology, College of Medicine, University of Saskatchewan, Academic Health Sciences Building, 107 Wiggins Rd, Saskatoon, SK S7N 5E5, Canada.
Taskia
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Mir
Shu Hui
SH
Huang
Kerri
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Kobryn
D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D025065:Borrelia burgdorferi / Q000201:enzymology*; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000378:metabolism*; D004706:Endodeoxyribonucleases / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D045522:Recombinases / Q000737:chemistry / Q000378:metabolism*; D016615:Telomere / Q000201:enzymology
D001426:Bacterial Proteins; D004277:DNA, Single-Stranded; D045522:Recombinases; D004706:Endodeoxyribonucleases; C446515:ResT protein, Borrelia