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Crystal structure of the Ctf18-1-8 module from Ctf18-RFC in complex with a 63 kDa fragment of DNA Polymerase epsilonCrystal structure of the Ctf18-1-8 module from Ctf18-RFC in complex with a 63 kDa fragment of DNA Polymerase epsilon
Structural highlights
Function[CTF18_YEAST] Essential for the fidelity of chromosome transmission. Required for the DNA replication block checkpoint. Component of the RFC-like complex CTF18-RFC which is required for efficient establishment of chromosome cohesion during S-phase and may load or unload POL30/PCNA. During a clamp loading circle, the RFC:clamp complex binds to DNA and the recognition of the double-stranded/single-stranded junction stimulates ATP hydrolysis by RFC. The complex presumably provides bipartite ATP sites in which one subunit supplies a catalytic site for hydrolysis of ATP bound to the neighboring subunit. Dissociation of RFC from the clamp leaves the clamp encircling DNA.[1] [2] [3] [4] [DPOE_YEAST] DNA polymerase epsilon (DNA polymerase II) participates in chromosomal DNA replication. It is required during synthesis of the leading and lagging DNA strands at the replication fork and binds at/or near replication origins and moves along DNA with the replication fork. It has 3'-5' proofreading exonuclease activity that correct errors arising during DNA replication. It is also involved in DNA synthesis during DNA repair.[5] [CTF8_YEAST] Essential for the fidelity of chromosome transmission. Required for the DNA replication block checkpoint. Component of the RFC-like complex CTF18-RFC which is required for efficient establishment of chromosome cohesion during S-phase and may load or unload POL30/PCNA. During a clamp loading circle, the RFC:clamp complex binds to DNA and the recognition of the double-stranded/single-stranded junction stimulates ATP hydrolysis by RFC. The complex presumably provides bipartite ATP sites in which one subunit supplies a catalytic site for hydrolysis of ATP bound to the neighboring subunit. Dissociation of RFC from the clamp leaves the clamp encircling DNA.[6] [7] [DCC1_YEAST] Component of the RFC-like complex CTF18-RFC which is required for efficient establishment of chromosome cohesion during S-phase and may load or unload POL30/PCNA. During a clamp loading circle, the RFC:clamp complex binds to DNA and the recognition of the double-stranded/single-stranded junction stimulates ATP hydrolysis by RFC. The complex presumably provides bipartite ATP sites in which one subunit supplies a catalytic site for hydrolysis of ATP bound to the neighboring subunit. Dissociation of RFC from the clamp leaves the clamp encircling DNA.[8] [9] Publication Abstract from PubMedCtf18-RFC is an alternative PCNA loader which plays important but poorly understood roles in multiple DNA replication-associated processes. To fulfill its specialist roles, the Ctf18-RFC clamp loader contains a unique module in which the Dcc1-Ctf8 complex is bound to the C terminus of Ctf18 (the Ctf18-1-8 module). Here, we report the structural and functional characterization of the heterotetrameric complex formed between Ctf18-1-8 and a 63 kDa fragment of DNA polymerase varepsilon. Our data reveal that Ctf18-1-8 binds stably to the polymerase and far from its other functional sites, suggesting that Ctf18-RFC could be associated with Pol varepsilon throughout normal replication as the leading strand clamp loader. We also show that Pol varepsilon and double-stranded DNA compete to bind the same winged-helix domain on Dcc1, with Pol varepsilon being the preferred binding partner, thus suggesting that there are two alternative pathways to recruit Ctf18-RFC to sites of replication. Structural Basis for the Recruitment of Ctf18-RFC to the Replisome.,Grabarczyk DB, Silkenat S, Kisker C Structure. 2017 Dec 6. pii: S0969-2126(17)30357-X. doi:, 10.1016/j.str.2017.11.004. PMID:29225079[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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