title: Purification and characterization of an activity from Saccharomyces cerevisiae that catalyzes homologous pairing and strand exchange.
abstract: An activity that catalyzes the formation of joint molecules from linear M13mp19 replicative form DNA and circular M13mp19 viral DNA was purified 1000- to 2000-fold from mitotic Saccharomyces cerevisiae cells. The activity appeared to reside in a Mr 132,000 polypeptide. The reaction required that the substrates be homologous and also required Mg2+. There was no requirement for ATP. The reaction required stoichiometric amounts of protein and showed a cooperative dependence on protein concentration. Electron microscopic analysis of the joint molecules indicated they were formed by displacement of one strand of the linear duplex by the single-stranded circular molecule. This analysis also showed that heteroduplex formation started at the 3'-homologous end of the linear duplex strand followed by extension of the hybrid region toward the 5'-homologous end of the linear duplex strand (3'-to-5' direction).
authors.forename: R
authors.initials: R
authors.lastname: Kolodner
authors.forename: D H
authors.initials: DH
authors.lastname: Evans
authors.forename: P T
authors.initials: PT
authors.lastname: Morrison
mesh_terms: D004247:DNA / Q000378:metabolism*; D004587:Electrophoresis, Agar Gel; D008854:Microscopy, Electron; D009690:Nucleic Acid Conformation; D012441:Saccharomyces cerevisiae / Q000032:analysis* / Q000235:genetics
chemical_list: D004247:DNA