Project/Area Number |
05454639
|
Research Category |
Grant-in-Aid for General Scientific Research (B)
|
Allocation Type | Single-year Grants |
Research Field |
Molecular biology
|
Research Institution | Nara Institute of Science and Technology (1994) The University of Tokyo (1993) |
Principal Investigator |
HISAJI Maki Nara Institute of Science and Technology, バイオサイエンス研究科, 教授 (20199649)
|
Project Period (FY) |
1993 – 1994
|
Project Status |
Completed (Fiscal Year 1994)
|
Budget Amount *help |
¥5,800,000 (Direct Cost: ¥5,800,000)
Fiscal Year 1994: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1993: ¥3,800,000 (Direct Cost: ¥3,800,000)
|
Keywords | Esherichia coli / Molecular Biology / Mutator / Mismatch repair / DNA replication |
Research Abstract |
8-Oxo-dGTP (8-oxo-7,8-dihydrodeoxyguanosine triphosphate) is a potent mutagenic substrate for DNA synthesis, and organisms possess enzymes specifically hydfolyzing 8-oxo-dGTP to the monophosphate form. The accumulatiom of 8-oxo-dGTP in the nucleotide pool induces G : C*T : A transversion as well as A : T*C : G transversion, and Escherichia coli cells possess mechanisms for preventing such mutations. From analyzes of forward mutations induced in cells lacking 8-oxo-dGTPase (MutT protein) and/or repair enzymes that suppress mutations caused by 8-oxoguanine DNA (MutM and MutY proteins), cooperative functions of these proteins in control of the spontaneous mutagenesis became evident. In mutator strains lacking MutT and/or MutM proteins, 8-oxoguanine of DNA increased to a concentration expected from the increased frequency of mutation.
|