Helicase Activation and Establishment of Replication Forks at Chromosomal Origins of Replication
Seiji Tanaka,Hiroyuki Araki +1 more
TLDR
Functional homologs of these proteins exist in metazoa, although pre-IC formation cannot be separated by requirement of DDK and CDK because of experimental limitations.Abstract:
Many replication proteins assemble on the pre-RC-formed replication origins and constitute the pre-initiation complex (pre-IC). This complex formation facilitates the conversion of Mcm2-7 in the pre-RC to an active DNA helicase, the Cdc45-Mcm-GINS (CMG) complex. Two protein kinases, cyclin-dependent kinase (CDK) and Dbf4-dependent kinase (DDK), work to complete the formation of the pre-IC. Each kinase is responsible for a distinct step of the process in yeast; Cdc45 associates with origins in a DDK-dependent manner, whereas the association of GINS with origins depends on CDK. These associations with origins also require specific initiation proteins: Sld3 for Cdc45; and Dpb11, Sld2, and Sld3 for GINS. Functional homologs of these proteins exist in metazoa, although pre-IC formation cannot be separated by requirement of DDK and CDK because of experimental limitations. Once the replicative helicase is activated, the origin DNA is unwound, and bidirectional replication forks are established.read more
Citations
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Journal ArticleDOI
Regulated eukaryotic DNA replication origin firing with purified proteins
TL;DR: The reconstitution of budding yeast DNA replication initiation with 16 purified replication factors, made from 42 polypeptides is described, which defines the minimum complement of proteins, protein kinase substrates and co-factors required for regulated eukaryotic DNA replication.
Journal ArticleDOI
Principles and concepts of DNA replication in bacteria, archaea, and eukarya
TL;DR: The general nature of the DNA replication machinery is outlined, but also points out important and key differences.
Journal ArticleDOI
How the Eukaryotic Replisome Achieves Rapid and Efficient DNA Replication.
TL;DR: It is proposed that switching between these DNA polymerases also contributes to leading-strand synthesis under conditions of replicative stress.
Journal ArticleDOI
Structure of the eukaryotic MCM complex at 3.8 A
Ningning Li,Yuanliang Zhai,Yixiao Zhang,Wanqiu Li,Maojun Yang,Jianlin Lei,Bik Kwoon Tye,Ning Gao +7 more
TL;DR: Cryo-electron microscopy reports a near-atomic structure of the MCM2–7 double hexamer purified from yeast G1 chromatin that shows unusual features of the twisted and tilted single hexamers that suggest a concerted mechanism for the melting of origin DNA that requires structural deformation of the intervening DNA.
Journal ArticleDOI
Mechanism of asymmetric polymerase assembly at the eukaryotic replication fork
Roxana E. Georgescu,Lance D. Langston,Nina Y. Yao,Olga Yurieva,Dan Zhang,Jeff Finkelstein,Tani Agarwal,Mike O'Donnell +7 more
TL;DR: Eukaryotes use distinct polymerases for leading- and lagging-strand replication, but how they target their respective strands is uncertain, and reconstituted Saccharomyces cerevisiae replication forks found that CMG helicase selects polymerase (Pol) ɛ to the exclusion of Pol δ on the leading strand.
References
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Journal ArticleDOI
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Journal ArticleDOI
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TL;DR: It is shown that, in budding yeast, hydroxyurea, which blocks the progression of replication forks from early-firing origins, also inhibits the firing of late origins, indicating that regulation of late origin firing may also be an important component of the ‘intra-S-phase’ checkpoint and may aid cell survival under adverse conditions.
Journal ArticleDOI
S-phase checkpoint proteins Tof1 and Mrc1 form a stable replication-pausing complex
Yuki Katou,Yutaka Kanoh,Masashige Bando,Hideki Noguchi,Hirokazu Tanaka,Toshihiko Ashikari,Katsunori Sugimoto,Katsuhiko Shirahige +7 more
TL;DR: It is demonstrated that the checkpoint regulatory proteins Tof1 and Mrc1 interact directly with the DNA replication machinery in Saccharomyces cerevisiae, which forms a stable pausing structure that serves to anchor subsequent DNA repair events.