| Structural highlights
1zqn is a 3 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | |
| Related: | 7ice, 7icf, 7icg, 7ich, 7ici, 7icj, 7ick, 7icl, 7icm, 7icn, 7ico, 7icp, 7icq, 7icr, 7ics, 7ict, 7icu, 7icv, 8ica, 8icb, 8icc, 8ice, 8icf, 8icg, 8ich, 8ici, 8icj, 8ick, 8icl, 8icm, 8icn, 8ico, 8icp, 8icq, 8icr, 8ics, 8ict, 8icu, 8icv, 8icw, 8icx, 8icy, 8icz, 9ica, 9icb, 9icc, 9ice, 9icf, 9icg, 9ich, 9ici, 9icj, 9ick, 9icl, 9icm, 9icn, 9ico, 9icp, 9icq, 9icr, 9ics, 9ict, 9icu, 9icv, 9icw, 9icx, 9icy, 1zqa, 1zqb, 1zqc, 1zqd, 1zqe, 1zqf, 1zqg, 1zqh, 1zqi, 1zqj, 1zqk, 1zql, 1zqm, 1zqo, 1zqp, 1zqq, 1zqr, 1zqs, 1zqt |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[DPOLB_HUMAN] Repair polymerase that plays a key role in base-excision repair. Has 5'-deoxyribose-5-phosphate lyase (dRP lyase) activity that removes the 5' sugar phosphate and also acts as a DNA polymerase that adds one nucleotide to the 3' end of the arising single-nucleotide gap. Conducts 'gap-filling' DNA synthesis in a stepwise distributive fashion rather than in a processive fashion as for other DNA polymerases.[1] [2] [3] [4]
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
X-ray crystallographic studies have shown that DNA binding by human polymerase beta (pol beta) occurs primarily through two structurally and sequentially homologous helix-hairpin-helix (HhH) motifs, one in the fingers subdomain and the other in the 8-kDa domain [Pelletier, H., Sawaya, M. R., Wolfle, W., Wilson, S. H., & Kraut, J. (1996a) Biochemistry 35, 12742-12761]. In that DNA binding by each HhH motif is facilitated by a metal ion, we set out to determine the identity of the metal ion that most likely binds to the HhH motif in vivo. Crystal soaking experiments were performed on human pol beta-DNA cocrystals with Mg2+, Ca2+, Na+, and K+, the four most prevalent metal ions in the cell, and in each case a data set was collected and the resulting structure was refined. Under the conditions tested, the HhH motifs of pol beta have an affinity for these biologically prevalent metal ions in the order Mg2+ < Ca2+ < Na+ < K+, with K+ displaying the strongest binding. Crystals soaked in the presence of Tl+, a commonly used spectroscopic probe for K+, were too X-ray-sensitive to establish the binding behavior of Tl+, but soaking experiments with Ba2+ and Cs+ resulted in relatively stable crystals that gave evidence of metal ion binding in both HhH motifs, confirming that larger monovalent and divalent metal ions are capable of binding to the HhH metal sites. Although Mn2+, which has been categorized as a potent polymerase mutagen, binds to the HhH motifs with a greater affinity than Mg2+, Mn2+ does not bind to the HhH motifs in the presence of equimolar concentrations of Na+. These results suggest that in vivo, where Mn2+ is present only in trace amounts, Mn2+ probably does not have a large effect on DNA binding and may instead manifest a mutagenic effect on pol beta primarily by distorting nucleotide binding or by directly affecting the catalytic step [Pelletier, H., Sawaya, M. R., Wolfle, W., Wilson, S. H., & Kraut, J. (1996b) Biochemistry 35, 12762-12777]. Crystal soaking experiments with 31-kDa apoenzyme crystals show that, in the absence of DNA, the HhH motif in the fingers subdomain binds metal ions with either much lower occupancy or not at all, indicating that metal ion binding is dependent on the presence of the DNA substrate.
Characterization of the metal ion binding helix-hairpin-helix motifs in human DNA polymerase beta by X-ray structural analysis.,Pelletier H, Sawaya MR Biochemistry. 1996 Oct 1;35(39):12778-87. PMID:8841120[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Bennett RA, Wilson DM 3rd, Wong D, Demple B. Interaction of human apurinic endonuclease and DNA polymerase beta in the base excision repair pathway. Proc Natl Acad Sci U S A. 1997 Jul 8;94(14):7166-9. PMID:9207062
- ↑ Matsumoto Y, Kim K, Katz DS, Feng JA. Catalytic center of DNA polymerase beta for excision of deoxyribose phosphate groups. Biochemistry. 1998 May 5;37(18):6456-64. PMID:9572863 doi:10.1021/bi9727545
- ↑ DeMott MS, Beyret E, Wong D, Bales BC, Hwang JT, Greenberg MM, Demple B. Covalent trapping of human DNA polymerase beta by the oxidative DNA lesion 2-deoxyribonolactone. J Biol Chem. 2002 Mar 8;277(10):7637-40. Epub 2002 Jan 22. PMID:11805079 doi:10.1074/jbc.C100577200
- ↑ Parsons JL, Dianova II, Khoronenkova SV, Edelmann MJ, Kessler BM, Dianov GL. USP47 is a deubiquitylating enzyme that regulates base excision repair by controlling steady-state levels of DNA polymerase beta. Mol Cell. 2011 Mar 4;41(5):609-15. doi: 10.1016/j.molcel.2011.02.016. PMID:21362556 doi:10.1016/j.molcel.2011.02.016
- ↑ Pelletier H, Sawaya MR. Characterization of the metal ion binding helix-hairpin-helix motifs in human DNA polymerase beta by X-ray structural analysis. Biochemistry. 1996 Oct 1;35(39):12778-87. PMID:8841120 doi:http://dx.doi.org/10.1021/bi960790i
|
