title: Identification and purification of DBF-A, a double-stranded DNA-binding protein from Saccharomyces cerevisiae.
abstract: Using oligonucleotide affinity chromatography with DNase I footprinting as an assay we have looked for proteins that interact with sequence elements within the yeast origin of replication, autonomously replicating sequence 1 (ARS1). In this work we describe a protein that binds with high affinity to DNA but displays only moderate sequence specificity. It is eluted at 0.7 M salt from an ARS1 oligonucleotide column. Footprinting analysis on ARS1 at a high protein concentration revealed at least three sites of protection flanking element A and its repeats. Element A itself is rendered hypersensitive to DNase I digestion upon protein binding. This pattern is also observed for the H4 and HMR-E ARSs, suggesting that the protein alters the DNA conformation at element A and its repeats. The affinity-purified fraction is also capable of supercoiling a relaxed, covalently closed plasmid in the presence of topoisomerase. Highly purified preparations of the protein are enriched in an 18-kDa polypeptide which can be renatured from a denaturing gel and shown to bind ARS1 DNA. We have designated this protein DBF-A, DNA-binding factor A.
authors.affiliation: Braun Laboratories, California Institute of Technology, Pasadena 91125.
authors.forename: R
authors.initials: R
authors.lastname: Verma
authors.forename: J L
authors.initials: JL
authors.lastname: Campbell
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D001483:Base Sequence; D002846:Chromatography, Affinity / Q000379:methods; D004261:DNA Replication; D004271:DNA, Fungal / Q000378:metabolism; D004278:DNA, Superhelical / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000302:isolation & purification* / Q000378:metabolism; D015151:Immunoblotting; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009838:Oligodeoxyribonucleotides; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins
chemical_list: C072277:DBF-A protein, S cerevisiae; D004271:DNA, Fungal; D004278:DNA, Superhelical; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D009838:Oligodeoxyribonucleotides; D029701:Saccharomyces cerevisiae Proteins; D000255:Adenosine Triphosphate