title: DNA unwinding activity of replication protein A.
abstract: Replication protein A (RP-A) is a heterotrimeric complex conserved in eukaryotic cells. It binds to single-stranded DNA and is essential for initiation and elongation of DNA replication. In this communication we give evidence that this protein can unwind DNA independent of magnesium and ATP, two essential cofactors for bona fide DNA helicase activity. RP-A can unwind up to at least 350 basepairs and appears to be required in stoichiometric amounts. The reaction is extremely sensitive to NaCl and MgCl2. This activity of RF-A is suggestive for a possible unwinding function in initiation of DNA replication in eukaryotes.
authors.affiliation: Department of Pharmacology and Biochemistry, University of Zürich-Irchel, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Georgaki
authors.forename: B
authors.initials: B
authors.lastname: Strack
authors.forename: V
authors.initials: V
authors.lastname: Podust
authors.forename: U
authors.initials: U
authors.lastname: Hübscher
mesh_terms: D000256:Adenoviridae / Q000378:metabolism; D004265:DNA Helicases / Q000187:drug effects / Q000378:metabolism*; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000187:drug effects / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D015636:Magnesium Chloride / Q000378:metabolism; D051716:Replication Protein A; D012965:Sodium Chloride / Q000378:metabolism; D013604:T-Phages / Q000378:metabolism; D013950:Thymus Gland / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D051716:Replication Protein A; D015636:Magnesium Chloride; D012965:Sodium Chloride; D004265:DNA Helicases