| Project/Area Number |
09044309
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Field |
Biological pharmacy
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| Research Institution | Okayama University |
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Principal Investigator |
HAYATSU Hikoya Okayama University, Faculty of Pharmaceutical Sciences, Professor, 薬学部, 教授 (10012593)
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| Co-Investigator(Kenkyū-buntansha) |
WILLIAMS David M Department of Chemistry, University of Sheffield, Demonstrator, 化学科, デモンストレーター
LOAKES David MRC Laboratory of Molecular Biology, Scientist, 分子生物学研究部, 研究員
BROWN Daniel M MRC Laboratory of Molecular Biology, Attached Scientific Worker, 分子生物学研究部, 特別研究職
SHIMAMOTO Tadashi Hiroshima University, Faculty of Applied Biological Science, Associate Professor, 生物生産学部, 助教授 (90187443)
NEGISHI Kazuo Okayama University, Gene Research Center, Associate Professor, 遺伝子実験施設, 助教授 (70116490)
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| Project Period (FY) |
1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 1997: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | P-nucleoside / Mutagenesis / nucleoside analog / DNA polymerase / AIDS virus / Nickel / Incorporation error / Reverse transcriptase |
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| Research Abstract |
We have analyzed the effect of nickel ion on the mutagenicity and replicational errors caused by dP.NiCl_2 inhibits GC-to-AT transitions induced by dP up to 50%. In contrast, NiCl_2 has weak enhancing effects on the dP-induced AT-to-GC.
To know the mechanism for this specific inhibition, we have analyzed the effects of NiCl_2 on the DNA synthesis on oligonucleotide templates using the large fragment of E.coli polymerase I.dPTP, and dP in the template can pair with both dA and dG.NiCl_2 inhibited the incorporation of both dPTP and dCTP opposite dG, but the inhibition of dPTP incorporation was greater than that of dCTP incorporation. NiCl_2 inhibits the incorporation of dPTP and dTTP opposite dA at the same efficiency. Ni^<2+> inhibited the incorporation of dGTP and dATP opposite dP,but there was no difference between dGTP and dATP.If NiCi2 has the same effects on the replicase in the E.coli cells, the specific inhibitory effect of NiCl2 on the dP mutagenesis can be explained by its effect on a DNA polymerase, .
We have also studied the incorporation of dPTP by a unique enzyme, E.coli reverse transcriptase. We found the enzyme can utilize dPTP efficiently. The analysis of the incorporation specificity is still underway.
The ribonucleoside triphosphate, rPTP,was synthesized this year at the first time. We found that rPTP can be incorporated in place of UTP efficiently in the in vitro synthesis of TARRNA,which is an AIDS-derived RNA binding to Tat, a AIDS virus transcription factor. We have synthsized TARRNA containg rP in place of rU.
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