title: Holliday junction formation by the Borrelia burgdorferi telomere resolvase, ResT: implications for the origin of genome linearity.
abstract: Spirochetes of the genus Borrelia include the causative agents of Lyme disease and relapsing fever. They possess unusual, highly segmented genomes composed mostly of linear replicons with covalently closed hairpin telomeres. The telomeres are formed from inverted repeat replicated telomere junctions (rTels) by the telomere resolvase, ResT. ResT uses a reaction mechanism with similarities to that employed by the type IB topoisomerases and tyrosine recombinases. Here, we report that the relationship of ResT to the tyrosine recombinases extends to the ability to synapse-replicated telomeres and to catalyse the formation of a Holliday junction. We also report that ResT can use asymmetrized substrates that mimic the properties of a recombination site for a tyrosine recombinase, to form Holliday junctions. We propose a model for how this explains the origin of genome linearity in the genus Borrelia.
authors.affiliation: Département de Microbiologie et d'Infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec J1H5N4, Canada. kerri.kobryn@usherbrooke.ca
authors.forename: Kerri
authors.initials: K
authors.lastname: Kobryn
authors.forename: Julien
authors.initials: J
authors.lastname: Briffotaux
authors.forename: Victor
authors.initials: V
authors.lastname: Karpov
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D025065:Borrelia burgdorferi / Q000201:enzymology* / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D045566:DNA, Cruciform / Q000378:metabolism*; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D016680:Genome, Bacterial; D045522:Recombinases / Q000378:metabolism; D013379:Substrate Specificity; D016615:Telomere / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D045566:DNA, Cruciform; D045522:Recombinases; D004706:Endodeoxyribonucleases; C446515:ResT protein, Borrelia