| Project/Area Number |
09460050
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
応用微生物学・応用生物化学
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
KINASHI Haruyasu Graduate School of Advanced Sciences of Matter, Department of Molecular Biotechnology, Professor, 大学院・先端物質科学研究科, 教授 (80224997)
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| Co-Investigator(Kenkyū-buntansha) |
SHINKAWA Hidenori Graduate School of Advanced Scienc-es of Matter, Department of Molecular Biotech, 大学院・先端物質科学研究科, 助教授 (50226338)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥12,600,000 (Direct Cost: ¥12,600,000)
Fiscal Year 1998: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1997: ¥10,800,000 (Direct Cost: ¥10,800,000)
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| Keywords | actinomycetes / Streptomyces / linear chromosome / genome project / terminal sequence / chromosomal deletion / chromosomal circularization / chromosomal recombination |
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| Research Abstract |
The structure of the linear chromosome of Streptomyces griseus strain 2247 and its dynamic rearrangements have been studied on molecular level, and the following results were obtained.
1. The nucleotide sequence of the chromosomal end of S.griseus 2247 was determined and compared with those of other Streptomyces linear chromosomes and plasmids. The conserved end sequence was not found there but several inverted repeats were. These sequences may form hairpin loops and function in replication of the linear DNA.
2. Many deletion mutants have been prepared by UV-irradiation of strain 2247. The relationship between the deletion size and topology of the mutant chromosomes suggests that some region near the afsA gene on the left side of the chromosome is essential for maintenance of the linear chromosome.
3. The fusion junctions of the circularized chromosomes in three mutants, 404-23, N2 and 83, were cloned and sequenced. The chromosomal circularization was deduced to occur by illegitimate recombination between the right and left deletion ends which do not have any homology to each other.
4. Only the mutant 301-22 keeps a linear chromosome. Complicated rearrangements were found to have occurred on its chromosome. Namely, the right arm of the chromosome was replaced by the left arm, and additionally a new fragment was attached to both deletion ends of the chromosome.
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