| Project/Area Number |
05454069
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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 |
応用微生物学・応用生物化学
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| Research Institution | UNIVERSITY OF TOKYO |
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Principal Investigator |
TAKAHASHI Hideo Institute of Molecular and Cellular Biosciences, Laboratory of Molecular Genetics and Breeding, Professor, 分子細胞生物学研究所, 教授 (90013333)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Kan Institute of Molecular and Cellular Biosciences, Laboratory of Molecular Genetic, 分子細胞生物学研究所, 助手 (60222113)
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| Project Period (FY) |
1993 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥7,500,000 (Direct Cost: ¥7,500,000)
Fiscal Year 1995: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1994: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1993: ¥5,500,000 (Direct Cost: ¥5,500,000)
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| Keywords | Sigma factor / sigma^<38> / stationary phase / Escherichia coli / promoter / RNA polymerase / functional domain / 主要シグマ因子 / σ38 / プロモーター特異性 |
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| Research Abstract |
This research was aimed to elucidate the relationships between structure and function of major-type sigma factors, especially a stationary phase-specific sigma^<38> (=rpoS gene product) of Escherichia coli. (1) RpoS protein was verified to be an RNA polymerase sigma factor by in vitro experiments performed using the re-constituted RNA polymerase holoenzyme containing the purified RpoS protein and named as sigma^<38> from its molecular mass (38 kDa). (2) E sigma^<38> recognized many of E sigma^<70>-type promoters whose-10 hexamer appeared to be crucial for the recognition. (3) Chimeric proteins constructed by recombining the rpoD and rpoS genes had a sigma activity and their recognition specificity was that from the expected functional domains of respective sigma protein. (4) Deletion derivatives of sigma^<38> missing a region of several amino acid residues between region 4.2 and the C-terminus showed higher sigma activity than the wild-type sigma^<38>. We proposed a new functional domain in the C-terminal region of major sigma proteins which may function as a modulator of sigma activity. (5) Deletion mutants of sigma^<38> completely missing the C-terminal portion after the region 4.2 still retained sigma activity, being consistent with the fact that sigma^<38> does not require a specific-35 hexamer sequence for its promoter recognition. (6) The rpoD gene products of cyanobacteria were demonstrated to have a sigma activities by in vitro trnscription experiments.
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