Mcm1 promotes replication initiation by binding specific elements at replication origins.
Mol Cell Biol
; 24(14): 6514-24, 2004 Jul.
Article
em En
| MEDLINE
| ID: mdl-15226450
ABSTRACT
Minichromosome maintenance protein 1 (Mcm1) is required for efficient replication of autonomously replicating sequence (ARS)-containing plasmids in yeast cells. Reduced DNA binding activity in the Mcm1-1 mutant protein (P97L) results in selective initiation of a subset of replication origins and causes instability of ARS-containing plasmids. This plasmid instability in the mcm1-1 mutant can be overcome for a subset of ARSs by the inclusion of flanking sequences. Previous work showed that Mcm1 binds sequences flanking the minimal functional domains of ARSs. Here, we dissected two conserved telomeric X ARSs, ARS120 (XARS6L) and ARS131a (XARS7R), that replicate with different efficiencies in the mcm1-1 mutant. We found that additional Mcm1 binding sites in the C domain of ARS120 that are missing in ARS131a are responsible for efficient replication of ARS120 in the mcm1-1 mutant. Mutating a conserved Mcm1 binding site in the C domain diminished replication efficiency in ARS120 in wild-type cells, and increasing the number of Mcm1 binding sites stimulated replication efficiency. Our results suggest that threshold occupancy of Mcm1 in the C domain of telomeric ARSs is required for efficient initiation. We propose that origin usage in Saccharomyces cerevisiae may be regulated by the occupancy of Mcm1 at replication origins.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
DNA
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Origem de Replicação
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Proteína 1 de Manutenção de Minicromossomo
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Replicação do DNA
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article