Clamp Loader Complex

Clamp Loader Complex

Clamp loader ATPases and the evolution of DNA replication

Apr 20, 2012 · Clamp loaders place sliding clamps at primer-template junctions for processive DNA replication. When bound to ATP, clamp loaders are competent to bind and open the sliding clamp protein. This ternary complex can now bind to a primer-template junction, which activates the ATPase activity of the clamp loader.

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The Mechanism of ATP-Dependent Primer-Template Recognition

May 15, 2009 · Figure 6: Binding of the ψ-peptide to the clamp loader collar (A) Isothermal titration calorimetry data for the binding of the ψ-peptide to the clamp loader complex. The calorimetric titration of 100 μM wild-type ψ-peptide into 10 μM of the clamp loader complex (left) and the ψ-peptide with Trp 17 mutated to Ser (right) are shown.

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The structure of the checkpoint clamp Liming complex and

The clamp loader (gamma complex, subunits gamma, delta, delta-prime) is required for loading the sliding clamp (beta) onto DNA. In T4 and related bacteriophages, such as RB69, the sliding clamp protein is gp45 and the clamp loader complex consists of the gp44 and gp62 proteins. In eukaryotes the sliding clamp is the PCNA (proliferating cell nuclear antigen) protein, and five …

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The clamp-loading complex for processive DNA replication

Jul 01, 2004 · A clamp loader complex loads such clamps onto the DNA strand by opening the clamp ring while at the same time binding and hydrolyzing ATP. All of the sliding clamps, including the Escherichia coli

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Structural analysis of the inactive state of the

Structural analysis of the inactive state of the Escherichia coliDNA polymerase clamp-loader complex Steven L. Kazmirski*†‡, Marjetka Podobnik*‡§, Tanya F. Weitze*†, Mike O'Donnell¶, and John Kuriyan*† *Department of Molecular and Cell Biology and Department of Chemistry, Howard Hughes Medical Institute, University of California, Berkeley, CA 94720;

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In Vitro Reconstitution of the Bacteriophage T4 Clamp

The clamp loader complex (CLC) of bacteriophage T4 is essential for viability and has analogs in both prokaryotes and eukaryotes. The gp44 and gp62 subunits of the T4 CLC, in a 4:1 ratio, tightly associate such that the two proteins co-purify. Using transformed Escherichia coli, we were able to demonstrate for the first time purification of the unique protein gp62 in the absence of gp44.

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O′Donnell Lab Learning

The PCNA clamp is the ring below the clamp loader. The 5 subunits of the RFC clamp loader are each a different color and arranged in a ring with a gap between two subunits, like the E. coli clamp loader. Adapted from: Bowman GD, O′Donnell M, Kuriyan J (2004). Structural analysis of a eukaryotic sliding DNA clamp-clamp loader complex.

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Structural mechanisms of sliding clamp loader ATPases

Feb 01, 2020 · In Aim 2, we investigate how the single subunit change in the clamp loader complex (Rfc1 replaced with Elg1) converts a dedicated clamp loader into a dedicated unloader. This work will not only reveal the mechanism and structure of a key protein involved in cancer development, but will also provide a blueprint for how an ATPase machine can be

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RCSB PDB - 1XXI: ADP Bound E. coli Clamp Loader Complex

Nov 05, 2004 · Clamp-loader complexes are heteropentameric AAA+ ATPases that load sliding clamps onto DNA. The structure of the nucleotide-free Escherichia coli clamp loader had been determined previously and led to the proposal that the clamp-loader cycles between an inactive state, in which the ATPase domains form a closed ring, and an active state that opens up to …

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The PCNA–RFC Families of DNA Clamps and Clamp Loaders

The clamp loader for the subunit sliding clamp is a complex consisting of the,,, 0,, and subunits of DNA polymerase III holoenzyme (8–10). This complex is not only involved in clamp loading but also in coordinating the leading and lagging strands at the replication fork (11). However, the simplest form of the clamp loader that will

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Clamp-loader | definition of clamp-loader by Medical

clamp-loader: ( klamp lōd'ĕr ), A multiprotein complex that catalyzes the assembly of circular sliding clamps on DNA to enable processive DNA replication. The complex binds primer template DNA and positions it in the center of a clamp to form a topologic link between the two.

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Structural analysis of a eukaryotic sliding DNA clamp

Structural analysis of a eukaryotic sliding DNA clamp-clamp loader complex. Sliding clamps are ring-shaped proteins that encircle DNA and confer high processivity on DNA polymerases. Here we report the crystal structure of the five-protein clamp loader complex (replication factor-C, RFC) of the yeast Saccharomyces cerevisiae, bound to the sliding clamp (proliferating cell n ….

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DNA Polymerase Clamp Loaders - UMass Med

Chromosomal DNA replication requires that DNA polymerases be tethered to ring-shaped sliding clamps that encircle the DNA and allow for high-speed, processive replication. Sliding clamps are loaded onto DNA by the clamp loader complex, a pentameric assembly of proteins of the AAA+ family of ATPases. We want to understand the function and mechanism of clamp loaders in …

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Introduction to Clamp Loading - Kuriyan Lab

The clamp loader (gamma complex, subunits gamma, delta, delta-prime) is required for loading the sliding clamp (beta) onto DNA. In T4 and related bacteriophages, such as RB69, the sliding clamp protein is gp45 and the clamp loader complex consists of the gp44 and gp62 proteins. In eukaryotes the sliding clamp is the PCNA (proliferating cell

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Allosteric communication in DNA polymerase clamp loaders

Apr 13, 2021 · The clamp-loader complex is referred to as a 'molecular matchmaker' because each productive cycle of ATP hydrolysis brings together a sliding clamp and DNA, which do not otherwise form a stable interaction (Sancar and Hearst, 1993). The clamp-loader cycle consists of …

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Communication between subunits within an archaeal clamp

May 17, 2006 · Although the amino-acid sequences and the protein complex compositions differ between the various systems, both the overall structure of the clamp/clamp-loader proteins and the molecular mechanisms of the clamp-loading process appear to …

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Elg1, an alternative subunit of the RFC clamp loader

Replication-factor C (RFC) is a protein complex that loads the processivity clamp PCNA onto DNA. Elg1 is a conserved protein with homology to the largest subunit of RFC, but its function remained enigmatic. Here, we show that yeast Elg1 interacts physically and genetically with PCNA, in a manner that depends on PCNA modification, and exhibits

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The β Sliding Clamp Closes around DNA prior to Release by

Escherichia coli γ complex clamp loader functions to load the β sliding clamp onto sites of DNA replication and repair. The clamp loader uses the energy of ATP binding and hydrolysis to drive conformational changes allowing for β binding and opening, DNA binding, and then release of the β·DNA complex. Although much work has been done studying the sliding clamp and clamp …

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DNA Replication in Prokaryotes | Smart Biology

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.

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Rad17 RFC-like complex | SGD

Complex: Rad17 RFC-like complex Macromolecular complex annotations are imported from the Complex Portal.These annotations have been derived from physical molecular interaction evidence extracted from the literature and cross-referenced in the entry, or by curator inference from information on homologs in closely related species or by inference from scientific …

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