The origin recognition complex in silencing, cell cycle progression, and DNA replication.
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.
Loo
S
S
Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA.
Fox
C A
CA
Rine
J
J
Kobayashi
R
R
Stillman
B
B
Bell
S
S
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
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