Human Dna Polymerase Kappa Encircles Dna: Implications for Mismatch Extension and Lesion Bypass.
From: Department of Structural and Chemical Biology, Mount Sinai School of Medicine, Box 1677, 1425 Madison Avenue, New York, NY 10029, USA.
Molecular cell
- Publish Date: Feb 2007
- ISSN: 1097-2765
- Volume: 25
- Issue: 4
- Pages: 601-14
- Medium: Print
- Language: English
- Citation (JAMA): Lone Samer, Townson Sharon A, Uljon Sacha N, et al. Human Dna Polymerase Kappa Encircles Dna: Implications for Mismatch Extension and Lesion Bypass.. Mol. Cell Feb 2007;25:601-14
Abstract
Human DNA polymerase kappa (Pol kappa) is a proficient extender of mispaired primer termini on undamaged DNAs and is implicated in the extension step of lesion bypass. We present here the structure of Pol kappa catalytic core in ternary complex with DNA and an incoming nucleotide. The structure reveals encirclement of the DNA by a unique “N-clasp” at the N terminus of Pol kappa, which augments the conventional right-handed grip on the DNA by the palm, fingers, and thumb domains and the PAD and provides additional thermodynamic stability. The structure also reveals an active-site cleft that is constrained by the close apposition of the N-clasp and the fingers domain, and therefore can accommodate only a single Watson-Crick base pair. Together, DNA encirclement and other structural features help explain Pol kappa’s ability to extend mismatches and to promote replication through various minor groove DNA lesions, by extending from the nucleotide incorporated opposite the lesion by another polymerase.
Mesh Headings (Keywords): Amino Acid Sequence, Base Pair Mismatch, Base Pairing, Binding Sites, Crystallography, X-Ray, DNA, DNA Adducts, DNA Damage, DNA Primers, DNA Replication, DNA-Directed DNA Polymerase, Humans, Kinetics, Models, Molecular, Molecular Sequence Data, Protein Binding, Protein Structure, Secondary, Pyrimidine Dimers
Check for Full Text / PubMed Unique Identifier (PMID): 17317631
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.