2bqu: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
No edit summary |
||
| Line 5: | Line 5: | ||
==Overview== | ==Overview== | ||
1,N(2)-Etheno(epsilon)guanine is a mutagenic DNA lesion derived from lipid, oxidation products and also from some chemical carcinogens. Gel, electrophoretic analysis of the products of primer extension by Sulfolobus, solfataricus P2 DNA polymerase IV (Dpo4) indicated preferential, incorporation of A opposite 3'-(1,N(2)-epsilon-G)TACT-5', among the four, dNTPs tested individually. With the template 3'-(1,N(2)-epsilon-G)CACT-5', both G and A were incorporated. When primer extension was done in the, presence of a mixture of all four dNTPs, high pressure liquid, chromatography-mass spectrometry analysis of the products indicated that, (opposite 3'-(1,N(2)-epsilon-G)CACT-5') the major product was 5'-GTGA-3', and the minor product was 5'-AGTGA-3'. With the template, ... | 1,N(2)-Etheno(epsilon)guanine is a mutagenic DNA lesion derived from lipid, oxidation products and also from some chemical carcinogens. Gel, electrophoretic analysis of the products of primer extension by Sulfolobus, solfataricus P2 DNA polymerase IV (Dpo4) indicated preferential, incorporation of A opposite 3'-(1,N(2)-epsilon-G)TACT-5', among the four, dNTPs tested individually. With the template 3'-(1,N(2)-epsilon-G)CACT-5', both G and A were incorporated. When primer extension was done in the, presence of a mixture of all four dNTPs, high pressure liquid, chromatography-mass spectrometry analysis of the products indicated that, (opposite 3'-(1,N(2)-epsilon-G)CACT-5') the major product was 5'-GTGA-3', and the minor product was 5'-AGTGA-3'. With the template, 3'-(1,N(2)-epsilon-G)TACT-5', the following four products were identified, by high pressure liquid chromatography-mass spectrometry: 5'-AATGA-3', 5'-ATTGA-3', 5'-ATGA-3', and 5'-TGA-3'. An x-ray crystal structure of Dpo4, was solved (2.1 A) with a primer-template and A placed in the primer to be, opposite the 1,N(2)-epsilon-G in the template 3'-(1,N(2)-epsilon-G)TACT, 5'. The added A in the primer was paired across the template T with, classic Watson-Crick geometry. Similar structures were observed in a, ternary Dpo4-DNA-dATP complex and a ternary Dpo4-DNA-ddATP complex, with, d(d)ATP opposite the template T. A similar structure was observed with a, ddGTP adjacent to the primer and opposite the C next to 1,N(2)-epsilon-G, in 3'-(1,N(2)-epsilon-G)CACT-5'. We concluded that Dpo4 uses several, mechanisms, including A incorporation opposite 1,N(2)-epsilon-G and also a, variation of dNTP-stabilized misalignment, to generate both base pair and, frameshift mutations. | ||
==About this Structure== | ==About this Structure== | ||
2BQU is a | 2BQU 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 DAD 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=2BQU OCA]. | ||
==Reference== | ==Reference== | ||
| Line 27: | Line 27: | ||
[[Category: translesion dna polymerase]] | [[Category: translesion dna polymerase]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 14:22:19 2007'' | ||
