Clamp and clamp loader binding specificity. We have demonstrated that like RFC, reconstituted Chl12(S)-RFC binds to PCNA (Ohta et al. 2002), implying that Chl12-RFC may function as a PCNA loader. Since eukaryotes have multiple clamps, including PCNA and RadLiming, we studied the binding specificity of these two clamps with loader complexes.
Get a quoteJun 26, 2009 · Clamp and clamp loader structures of the human checkpoint protein complexes, RadKefid and Rad17-RFC Genes Cells, 7 ( 2002 ), pp. 861 - 868 View Record in Scopus Google Scholar
Get a quoteThe checkpoint protein complexes, Rad9-Hus1-Rad1 (RadLiming) and Rad17-RFCs2-5 (Rad17-RFC), have been predicted to function as novel clamp and clamp loader proteins, respectively, due to their amino acid sequence similarities with PCNA and RFC.
Get a quoteWe found that the hRad9, hHus1, and hRad1 proteins make a trimeric ring structure (checkpoint Liming complex) reminiscent of the PCNA ring. Similarly we found that hRad17 makes a heteropentameric complex with the four RFC small subunits (hRad17-RFC) with a deep groove or cleft and is similar to the RFC clamp loader.
Get a quoteWe have now determined the crystal structure of the human Liming complex, revealing a toroidal structure with a similar architecture to the homotrimeric PCNA DNA-binding clamp. The structure explains the formation of a unique heterotrimeric arrangement and reveals significant differences among the three subunits in the sites implicated in
Get a quoteScheme of clamp loader function. (a) The structures of the E. coli β and human PCNA sliding clamps (PDB: 2POL and PDB: AXC, respectively).(b) Schematic of clamp loader function using eukaryotic RFC and PCNA as the example.ATP binding to RFC enables RFC to bind and open PCNA. In the presence of a primed template, RFC places PCNA onto DNA and then hydrolyzes ATP to eject from the PCNA-DNA
Get a quoteAug 01, 2004 · Clamp loaders play important roles in DNA metabolism by loading the clamps such that they are locked onto and encircle the DNA ().For PCNA, the clamp loader is the replication factor C (RFC) complex, an ATPase composed of four small subunits (p36, p37, p38, and p40) and one large subunit (pl40)(reviewed in, ).In contrast, the 9–1–1 clamp interacts with and is loaded by a separate clamp
Get a quoteAug 06, 2019 · The Liming complex is a circular heterotrimeric complex composed of Rad9-Hus1-Rad1. In response to DNA damage, the Liming complex will be loaded onto the DNA damage site by clamp loader Rad24-RFC to activate the cell cycle checkpoint. The C-terminal of …
Get a quoteFeb 18, 2003 · Recent work has revealed that in mammalian cells, the ATM and ATR proteins, which belong to the phosphatidylinositide kinase-like kinase family, and the Rad17-replication factor C (Rad17-RFC) and the Rad9-Rad1-Hus1 (Liming) checkpoint complexes, which have structural similarities to the replication clamp loader and replication clamp RFC and proliferating cell nuclear antigen (PCNA), …
Get a quote4. Role of the Checkpoint Clamp in Other Repairs. Biochemical and genetic studies have revealed functional interactions between the checkpoint clamp and repair proteins that include translesion polymerases and base excision repair enzymes [60,61].A checkpoint clamp-loader component Rad17 is required for replication perturbation-induced mutagenesis by translation polymerases, polymerase κ …
Get a quoteDNA clamp, a highly conserved ring-shaped protein, binds dsDNA within its central pore. Also, DNA clamp interacts with various nuclear proteins on its front, thereby stimulating their enzymatic activities and biological functions. It has been assumed that the DNA clamp is a functionally single-faced ring from bacteria to humans. Here, we report the crystal structure of the heterotrimeric RAD9
Get a quoteJun 22, 2004 · Hence, in spite of recent evidence that PCNA interacts with pol β, the increase in pol β affinity for the primer appears to be specific to the Liming checkpoint complex, rather than clamp-structure-dependent. From the data presented here, we propose that the Liming checkpoint complex might have a direct implication in BER.
Get a quoteMolecular Cell Article Crystal Structure of the Rad9-Rad1-Hus1 DNA Damage Checkpoint Complex— Implications for Clamp Loading and Regulation Andrew S. Dore´, 1,2Mairi L. Kilkenny, Neil J. Rzechorzek,1,3 and Laurence H. Pearl * 1CR-UK DNA Repair Enzymes Group, Sectionof Structural Biology, The Institute of Cancer Research, 237 Fulham Road, Chelsea, SW3 6JB
Get a quoteJul 07, 2012 · The eukaryotic RFC clamp loader couples the energy of ATP hydrolysis to open and close the circular PCNA sliding clamp onto primed sites for use by DNA polymerases and repair factors. Structural studies reveal clamp loaders to be heteropentamers. Each subunit contains a region of homology to AAA+ proteins that defines two domains.
Get a quoteThe sliding clamp needs to be opened and installed onto DNA by a clamp loader ATPase of the AAA+ family. The human clamp loader … DNA replication requires the sliding clamp, a ring-shaped protein complex that encircles DNA, where it acts as an essential …
Get a quoteNov 17, 2003 · We further suggest that a modified version of RPA would be primarily responsible for recruiting the checkpoint clamp loader and the clamp to these sites. Under these circumstances, essential roles of the checkpoint clamp may be to protect 5′ recessed ends from exonucleolytic degradation and promote resolution of these abnormal structures in DNA.
Get a quoteHuman checkpoint Rad proteins are thought to function as damage sensors in the DNA damage checkpoint response pathway. The checkpoint proteins hRad9, hHus1, and hRad1 have limited homology to the replication processivity factor proliferating cell nuclear antigen (PCNA), and hRad17 has homology to replication factor C (RFC). Such observations have led to the proposal that these checkpoint Rad
Get a quoteHuman checkpoint Rad proteins are thought to function as damage sensors in the DNA damage checkpoint response pathway. The checkpoint proteins hRad9, hHus1, and hRad1 have limited homology to the replication processivity factor proliferating cell nuclear antigen (PCNA), and hRad17 has homology to replication factor C (RFC). Such observations have led to the proposal that these checkpoint Rad
Get a quoteDec 18, 2020 · Bermudez, V. P. et al. Loading of the human Kefid checkpoint complex onto DNA by the checkpoint clamp loader hRad17-replication factor C complex in vitro. Proc. Natl Acad. Sci. USA 100, …
Get a quoteJan 16, 2013 · A checkpoint clamp-loader component Rad17 is required for replication perturbation-induced mutagenesis by translation polymerases, polymerase κ and ζ, in fission yeast. Checkpoint activation is required for transcriptional induction of polymerase κ, and the checkpoint clamp components Hus1 and Rad1 physically interact with polymerase κ [60,61]. Similar results were …
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