2HIK

heterotrimeric PCNA sliding clamp

Summary for 2HIK

• Entry DOI: 10.2210/pdb2hik/pdb
• Related: 2HII 2HIV 2HIX
• Descriptor: PCNA1 (SSO0397), PCNA2 (SSO1047), PCNA3 (SSO0405) (3 entities in total)
• Functional Keywords: pcna sliding clamp, processivity factor, dna replication, heterotrimer, replication
• Biological source: Sulfolobus solfataricus; More
• Total number of polymer chains: 9
• Total formula weight: 256378.33

Authors

Pascal, J.M.,Tsodikov, O.V.,Ellenberger, T. (deposition date: 2006-06-29, release date: 2006-11-07, Last modification date: 2024-11-20)

Primary citation

Pascal, J.M.,Tsodikov, O.V.,Hura, G.L.,Song, W.,Cotner, E.A.,Classen, S.,Tomkinson, A.E.,Tainer, J.A.,Ellenberger, T.
A Flexible Interface between DNA Ligase and PCNA Supports Conformational Switching and Efficient Ligation of DNA.
Mol.Cell, 24:279-291, 2006

PubMed Abstract: DNA sliding clamps encircle DNA and provide binding sites for many DNA-processing enzymes. However, it is largely unknown how sliding clamps like proliferating cell nuclear antigen (PCNA) coordinate multistep DNA transactions. We have determined structures of Sulfolobus solfataricus DNA ligase and heterotrimeric PCNA separately by X-ray diffraction and in complex by small-angle X-ray scattering (SAXS). Three distinct PCNA subunits assemble into a protein ring resembling the homotrimeric PCNA of humans but with three unique protein-binding sites. In the absence of nicked DNA, the Sulfolobus solfataricus DNA ligase has an open, extended conformation. When complexed with heterotrimeric PCNA, the DNA ligase binds to the PCNA3 subunit and ligase retains an open, extended conformation. A closed, ring-shaped conformation of ligase catalyzes a DNA end-joining reaction that is strongly stimulated by PCNA. This open-to-closed switch in the conformation of DNA ligase is accommodated by a malleable interface with PCNA that serves as an efficient platform for DNA ligation.

PubMed: 17052461
DOI: 10.1016/j.molcel.2006.08.015

Experimental method

X-RAY DIFFRACTION (3.3 Å)