1991 Fiscal Year Final Research Report Summary
The Structure of RecA Protein in Escherichia Coli.
| Project/Area Number |
01480539
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
分子遺伝学・分子生理学
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| Research Institution | Osaka University |
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Principal Investigator |
OGAWA Tomoko Osaka Univ., Dept. of Bio., Asistant Professor, 理学部, 講師 (80028208)
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| Co-Investigator(Kenkyū-buntansha) |
OGAWA Hideyuki Osaka Univ., Dept. of Biol., Professor., 理学部, 教授 (70028207)
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| Project Period (FY) |
1989 – 1991
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| Keywords | RecA Protein / RecA Protein Structure / Chimeric gene. / Chimeric RecA Protein / RecBCsbcA gene in E. coli. / Recombination / Oligomerization of RecA Protein / RecA gene of Pseudomonas aeruginosa / SOSresponce |
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| Research Abstract |
We developed a novel genetic method for finding functional regions of a protein by the analysis of chimeras formed between homologous proteins. Sets of chimeric genes were made by intramolecular homologous recombination in a linearized plasmid DNA carrying both recA genes of Escherichia coli and Pseudomonas aeruginosa. A recBCsbcA strain of E. coli was used for isolation of plasmids carrying recombinants between these genes. Examination of properties of E. coli strains deleting the recA gene and carrying a plasmid with a chimeric gene shows that chimera formation at certain positions inactivates a RecA function. Frequently, all chimeras with a junction in a certain region of the protein inactivate a function. Rather than a direct effect of the presence of the junction at a particular position, mismatching of the regions both sides of the junction that are derived from the different species is responsible for the inactivation. For a chimeric protein to be functional, certain pairs of sequences in different regions of the protein must derive from the same parent. Four pairs of such sequences were found : two are involved in activities for genetic recombination and for resistance to ultraviolet light irradiation and the others in formation of active oligomera. Regions defined by these sequences are located in the looped regions of the protein. A pair of regions may cooperate to form a functional folded structure.
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