2c22: Difference between revisions
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==Overview== | ==Overview== | ||
DNA polymerases insert dATP opposite the oxidative damage product, 7,8-dihydro-8-oxodeoxyguanosine (8-oxoG) instead of dCTP, to the extent of, >90% with some polymerases. Steady-state kinetics with the Y-family, Sulfolobus solfataricus DNA polymerase IV (Dpo4) showed 90-fold higher, incorporation efficiency of dCTP > dATP opposite 8-oxoG and 4-fold higher, efficiency of extension beyond an 8-oxoG:C pair than an 8-oxoG:A pair. The, catalytic efficiency for these events (with dCTP or C) was similar for G, and 8-oxoG templates. Mass spectral analysis of extended DNA primers, showed >/=95% incorporation of dCTP > dATP opposite 8-oxoG., Pre-steady-state kinetics showed faster rates of dCTP incorporation, opposite 8-oxoG than G. The measured K(d)(,dCTP) was 15-fold lower for an, ... | DNA polymerases insert dATP opposite the oxidative damage product, 7,8-dihydro-8-oxodeoxyguanosine (8-oxoG) instead of dCTP, to the extent of, >90% with some polymerases. Steady-state kinetics with the Y-family, Sulfolobus solfataricus DNA polymerase IV (Dpo4) showed 90-fold higher, incorporation efficiency of dCTP > dATP opposite 8-oxoG and 4-fold higher, efficiency of extension beyond an 8-oxoG:C pair than an 8-oxoG:A pair. The, catalytic efficiency for these events (with dCTP or C) was similar for G, and 8-oxoG templates. Mass spectral analysis of extended DNA primers, showed >/=95% incorporation of dCTP > dATP opposite 8-oxoG., Pre-steady-state kinetics showed faster rates of dCTP incorporation, opposite 8-oxoG than G. The measured K(d)(,dCTP) was 15-fold lower for an, oligonucleotide containing 8-oxoG than with G. Extension beyond an, 8-oxoG:C pair was similar to G:C and faster than for an 8-oxoG:A pair, in, contrast to other polymerases. The E(a) for dCTP insertion opposite 8-oxoG, was lower than for opposite G. Crystal structures of Dpo4 complexes with, oligonucleotides were solved with C, A, and G nucleoside triphosphates, placed opposite 8-oxoG. With ddCTP, dCTP, and dATP the phosphodiester, bonds were formed even in the presence of Ca(2+). The 8-oxoG:C pair showed, classic Watson-Crick geometry; the 8-oxoG:A pair was in the syn:anti, configuration, with the A hybridized in a Hoogsteen pair with 8-oxoG. With, dGTP placed opposite 8-oxoG, pairing was not to the 8-oxoG but to the 5' C, (and in classic Watson-Crick geometry), consistent with the low frequency, of this frameshift event observed in the catalytic assays. | ||
==About this Structure== | ==About this Structure== | ||
2C22 is a | 2C22 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sulfolobus_solfataricus Sulfolobus solfataricus] with CA and DGT as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/DNA-directed_DNA_polymerase DNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.7 2.7.7.7] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2C22 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: translesion dna polymerase]] | [[Category: translesion dna polymerase]] | ||
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Revision as of 13:42, 5 November 2007
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EFFICIENT AND HIGH FIDELITY INCORPORATION OF DCTP OPPOSITE 7,8-DIHYDRO-8-OXODEOXYGUANOSINE BY SULFOLOBUS SOLFATARICUS DNA POLYMERASE DPO4
OverviewOverview
DNA polymerases insert dATP opposite the oxidative damage product, 7,8-dihydro-8-oxodeoxyguanosine (8-oxoG) instead of dCTP, to the extent of, >90% with some polymerases. Steady-state kinetics with the Y-family, Sulfolobus solfataricus DNA polymerase IV (Dpo4) showed 90-fold higher, incorporation efficiency of dCTP > dATP opposite 8-oxoG and 4-fold higher, efficiency of extension beyond an 8-oxoG:C pair than an 8-oxoG:A pair. The, catalytic efficiency for these events (with dCTP or C) was similar for G, and 8-oxoG templates. Mass spectral analysis of extended DNA primers, showed >/=95% incorporation of dCTP > dATP opposite 8-oxoG., Pre-steady-state kinetics showed faster rates of dCTP incorporation, opposite 8-oxoG than G. The measured K(d)(,dCTP) was 15-fold lower for an, oligonucleotide containing 8-oxoG than with G. Extension beyond an, 8-oxoG:C pair was similar to G:C and faster than for an 8-oxoG:A pair, in, contrast to other polymerases. The E(a) for dCTP insertion opposite 8-oxoG, was lower than for opposite G. Crystal structures of Dpo4 complexes with, oligonucleotides were solved with C, A, and G nucleoside triphosphates, placed opposite 8-oxoG. With ddCTP, dCTP, and dATP the phosphodiester, bonds were formed even in the presence of Ca(2+). The 8-oxoG:C pair showed, classic Watson-Crick geometry; the 8-oxoG:A pair was in the syn:anti, configuration, with the A hybridized in a Hoogsteen pair with 8-oxoG. With, dGTP placed opposite 8-oxoG, pairing was not to the 8-oxoG but to the 5' C, (and in classic Watson-Crick geometry), consistent with the low frequency, of this frameshift event observed in the catalytic assays.
About this StructureAbout this Structure
2C22 is a Single protein structure of sequence from Sulfolobus solfataricus with CA and DGT as ligands. Active as DNA-directed DNA polymerase, with EC number 2.7.7.7 Structure known Active Site: AC1. Full crystallographic information is available from OCA.
ReferenceReference
Efficient and high fidelity incorporation of dCTP opposite 7,8-dihydro-8-oxodeoxyguanosine by Sulfolobus solfataricus DNA polymerase Dpo4., Zang H, Irimia A, Choi JY, Angel KC, Loukachevitch LV, Egli M, Guengerich FP, J Biol Chem. 2006 Jan 27;281(4):2358-72. Epub 2005 Nov 22. PMID:16306039
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- DNA-directed DNA polymerase
- Single protein
- Sulfolobus solfataricus
- Egli, M.
- Irimia, A.
- Loukachevitch, L.V.
- CA
- DGT
- 7
- 8-dihydro-8-oxodeoxyguanosine
- Dna damage
- Dna repair
- Dna replication
- Dna-binding
- Dna-directed dna polymerase
- Magnesium
- Metal -binding
- Mutator protein
- Nucleotidyltransferase
- P2 dna polymerase iv
- Transferase
- Translesion dna polymerase