title: The origin recognition complex in silencing, cell cycle progression, and DNA replication.
abstract: This report describes the isolation of ORC5, the gene encoding the fifth largest subunit of the origin recognition complex, and the properties of mutants with a defective allele of ORC5. The orc5-1 mutation caused temperature-sensitive growth and, at the restrictive temperature, caused cell cycle arrest. At the permissive temperature, the orc5-1 mutation caused an elevated plasmid loss rate that could be suppressed by additional tandem origins of DNA replication. The sequence of ORC5 revealed a potential ATP binding site, making Orc5p a candidate for a subunit that mediates the ATP-dependent binding of ORC to origins. Genetic interactions among orc2-1 and orc5-1 and other cell cycle genes provided further evidence for a role for the origin recognition complex (ORC) in DNA replication. The silencing defect caused by orc5-1 strengthened previous connections between ORC and silencing, and combined with the phenotypes caused by orc2 mutations, suggested that the complex itself functions in both processes.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA.
authors.forename: S
authors.initials: S
authors.lastname: Loo
authors.forename: C A
authors.initials: CA
authors.lastname: Fox
authors.forename: J
authors.initials: J
authors.lastname: Rine
authors.forename: R
authors.initials: R
authors.lastname: Kobayashi
authors.forename: B
authors.initials: B
authors.lastname: Stillman
authors.forename: S
authors.initials: S
authors.lastname: Bell
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002453:Cell Cycle / Q000235:genetics; D018797:Cell Cycle Proteins / Q000378:metabolism; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D004261:DNA Replication; D004271:DNA, Fungal / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D009154:Mutation; D051738:Origin Recognition Complex; D010641:Phenotype; D010957:Plasmids / Q000096:biosynthesis; D016133:Polymerase Chain Reaction; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D013696:Temperature; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; C497215:ORC2 protein, S cerevisiae; C497220:ORC5 protein, S cerevisiae; D051738:Origin Recognition Complex; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins