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Dpb11 protein helps control assembly of the Cdc45·Mcm2-7·GINS replication fork helicase.

Title: Dpb11 protein helps control assembly of the Cdc45·Mcm2-7·GINS replication fork helicase.
Name(s): Dhingra, Nalini, author
Bruck, Irina, author
Smith, Skye, author
Ning, Boting, author
Kaplan, Daniel L, author
Type of Resource: text
Genre: Journal Article
Date Issued: 2015-03-20
Physical Form: computer
online resource
Extent: 1 online resource
Language(s): English
Abstract/Description: Dpb11 is required for the initiation of DNA replication in budding yeast. Dpb11 binds to S-phase cyclin-dependent kinase-phosphorylated Sld2 and Sld3 to form a ternary complex during S phase. The replication fork helicase in eukaryotes is composed of Cdc45, Mcm2-7, and GINS. We show here, using purified proteins from budding yeast, that Dpb11 alone binds to Mcm2-7 and that Dpb11 also competes with GINS for binding to Mcm2-7. Furthermore, Dpb11 binds directly to single-stranded DNA (ssDNA), and ssDNA inhibits the Dpb11 interaction with Mcm2-7. We also found that Dpb11 can recruit Cdc45 to Mcm2-7. We identified a mutant of the BRCT4 motif of Dpb11 that remains bound to Mcm2-7 in the presence of ssDNA (dpb11-m1,m2,m3,m5), and this mutant exhibits a DNA replication defect when expressed in budding yeast cells. Expression of this mutant results in increased interaction between Dpb11 and Mcm2-7 during S phase, impaired GINS interaction with Mcm2-7 during S phase, and decreased replication protein A (RPA) interaction with origin DNA during S phase. We propose a model in which Dpb11 first recruits Cdc45 to Mcm2-7. Dpb11, although bound to Cdc45·Mcm2-7, can block the interaction between GINS and Mcm2-7. Upon extrusion of ssDNA from the central channel of Mcm2-7, Dpb11 dissociates from Mcm2-7, and Dpb11 binds to ssDNA, thereby allowing GINS to bind to Cdc45·Mcm2-7. Finally, we propose that Dpb11 functions with Sld2 and Sld3 to help control the assembly of the replication fork helicase.
Identifier: FSU_pmch_25659432 (IID), 10.1074/jbc.M115.640383 (DOI), PMC4367264 (PMCID), 25659432 (RID), 25659432 (EID), M115.640383 (PII)
Keywords: Cell Cycle, Cyclin-dependent Kinase (CDK), DNA, DNA Helicase, DNA Replication
Publication Note: This NIH-funded author manuscript originally appeared in PubMed Central at
Subject(s): Base Sequence
Cell Cycle Proteins/genetics
Cell Cycle Proteins/metabolism
Cell Cycle Proteins/physiology
Cloning, Molecular
DNA Helicases/metabolism
DNA Replication
DNA, Fungal/genetics
DNA, Fungal/metabolism
DNA, Single-Stranded/metabolism
DNA-Binding Proteins/metabolism
Minichromosome Maintenance Proteins/metabolism
Molecular Sequence Data
Nuclear Proteins/metabolism
Protein Binding
Saccharomyces cerevisiae/physiology
Saccharomyces cerevisiae Proteins/genetics
Saccharomyces cerevisiae Proteins/metabolism
Saccharomyces cerevisiae Proteins/physiology
Persistent Link to This Record:
Owner Institution: FSU
Is Part Of: The Journal of biological chemistry.
Issue: iss. 12, vol. 290

Choose the citation style.
Dhingra, N., Bruck, I., Smith, S., Ning, B., & Kaplan, D. L. (2015). Dpb11 protein helps control assembly of the Cdc45·Mcm2-7·GINS replication fork helicase. The Journal Of Biological Chemistry. Retrieved from