| Structural highlights
Function
[POLK_HUMAN] DNA polymerase specifically involved in DNA repair. Plays an important role in translesion synthesis, where the normal high-fidelity DNA polymerases cannot proceed and DNA synthesis stalls. Depending on the context, it inserts the correct base, but causes frequent base transitions, transversions and frameshifts. Lacks 3'-5' proofreading exonuclease activity. Forms a Schiff base with 5'-deoxyribose phosphate at abasic sites, but does not have lyase activity.[1] [2] [3] [4] [5] [6] [7]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Human polymerase kappa (hPol kappa) is one of four eukaryotic Y-class DNA polymerases and may be an important element in the cellular response to polycyclic aromatic hydrocarbons such as benzo[a]pyrene, which can lead to reactive oxygenated metabolite-mediated oxidative stress. Here, we present a detailed analysis of the activity and specificity of hPol kappa bypass opposite the major oxidative adduct 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxoG). Unlike its archaeal homolog Dpo4, hPol kappa bypasses this lesion in an error-prone fashion by inserting mainly dATP. Analysis of transient-state kinetics shows diminished "bursts" for dATP:8-oxoG and dCTP:8-oxoG incorporation, indicative of non-productive complex formation, but dATP:8-oxoG insertion events that do occur are 2-fold more efficient than dCTP:G insertion events. Crystal structures of ternary hPol kappa complexes with adducted template-primer DNA reveal non-productive (dGTP and dATP) alignments of incoming nucleotide and 8-oxoG. Structural limitations placed upon the hPol kappa by interactions between the N-clasp and finger domains combined with stabilization of the syn-oriented template 8-oxoG through the side chain of Met-135 both appear to contribute to error-prone bypass. Mutating Leu-508 in the little finger domain of hPol kappa to lysine modulates the insertion opposite 8-oxoG toward more accurate bypass, similar to previous findings with Dpo4. Our structural and activity data provide insight into important mechanistic aspects of error-prone bypass of 8-oxoG by hPol kappa compared with accurate and efficient bypass of the lesion by Dpo4 and polymerase eta.
Structural and functional elucidation of the mechanism promoting error-prone synthesis by human DNA polymerase kappa opposite the 7,8-dihydro-8-oxo-2'-deoxyguanosine adduct.,Irimia A, Eoff RL, Guengerich FP, Egli M J Biol Chem. 2009 Aug 14;284(33):22467-80. Epub 2009 Jun 19. PMID:19542228[8]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Ogi T, Kato T Jr, Kato T, Ohmori H. Mutation enhancement by DINB1, a mammalian homologue of the Escherichia coli mutagenesis protein dinB. Genes Cells. 1999 Nov;4(11):607-18. PMID:10620008
- ↑ Gerlach VL, Feaver WJ, Fischhaber PL, Friedberg EC. Purification and characterization of pol kappa, a DNA polymerase encoded by the human DINB1 gene. J Biol Chem. 2001 Jan 5;276(1):92-8. PMID:11024016 doi:http://dx.doi.org/10.1074/jbc.M004413200
- ↑ Fischhaber PL, Gerlach VL, Feaver WJ, Hatahet Z, Wallace SS, Friedberg EC. Human DNA polymerase kappa bypasses and extends beyond thymine glycols during translesion synthesis in vitro, preferentially incorporating correct nucleotides. J Biol Chem. 2002 Oct 4;277(40):37604-11. Epub 2002 Jul 26. PMID:12145297 doi:10.1074/jbc.M206027200
- ↑ Haracska L, Prakash L, Prakash S. Role of human DNA polymerase kappa as an extender in translesion synthesis. Proc Natl Acad Sci U S A. 2002 Dec 10;99(25):16000-5. Epub 2002 Nov 20. PMID:12444249 doi:10.1073/pnas.252524999
- ↑ Wolfle WT, Washington MT, Prakash L, Prakash S. Human DNA polymerase kappa uses template-primer misalignment as a novel means for extending mispaired termini and for generating single-base deletions. Genes Dev. 2003 Sep 1;17(17):2191-9. PMID:12952891 doi:http://dx.doi.org/10.1101/gad.1108603
- ↑ Haracska L, Prakash L, Prakash S. A mechanism for the exclusion of low-fidelity human Y-family DNA polymerases from base excision repair. Genes Dev. 2003 Nov 15;17(22):2777-85. PMID:14630940 doi:10.1101/gad.1146103
- ↑ Yasui M, Suzuki N, Miller H, Matsuda T, Matsui S, Shibutani S. Translesion synthesis past 2'-deoxyxanthosine, a nitric oxide-derived DNA adduct, by mammalian DNA polymerases. J Mol Biol. 2004 Nov 26;344(3):665-74. PMID:15533436 doi:S0022-2836(04)01222-7
- ↑ Irimia A, Eoff RL, Guengerich FP, Egli M. Structural and functional elucidation of the mechanism promoting error-prone synthesis by human DNA polymerase kappa opposite the 7,8-dihydro-8-oxo-2'-deoxyguanosine adduct. J Biol Chem. 2009 Aug 14;284(33):22467-80. Epub 2009 Jun 19. PMID:19542228 doi:10.1074/jbc.M109.003905
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