1988 Fiscal Year Final Research Report Summary
Molecular Construction of Cytochrome bc_1 and b_6/f Complexes
| Project/Area Number |
62470148
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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 |
物質生物化学
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| Research Institution | Osaka University |
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Principal Investigator |
MATSUBARA Hiroshi Faculty of Science, Osaka University Professor, 理学部, 教授 (00028242)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIKAWA Shinya Basic Research Institute of Technology, Himeji Technology University Professor, 工学基礎研究所, 教授 (40068119)
TAKAHASHI Yasuhiro The same as above Research assistant, 理学部, 助手 (10154874)
WAKABAYASHI Sadao The same as above Research assistant, 理学部, 助手 (80148436)
FUKUYAMA Keiichi The same as above assistant Professor, 理学部, 講師 (80032283)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Cytochrome bc_1 Complex / Euglena Cytochrome C_1 / Yeast Cytochrome C_1 / Cyanobacterial Cytochrome b_6 / f Complex / Terminal Oxidase |
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| Research Abstract |
1. A new method was developed for the isolation of cytochrome bc_1 complex from beef heart mitochondria. This method shortens the practical working period and raises the yield of the complex. However, several trials to crystallize the complex thus prepared were unsuccessful in X-ray diffraction analysis.
2. Euglena cytochrome bc_1 complex was prepared from its submitochondrial particles. The subunit composition of this complex was similar to those from other sources containing cytochromes b__- and c__-_1 and iron-sulfur protein with other several subunits. However, the -peak of cytochrome c__-_1 was found at 561nm and that of pyridine ferror=hemechrome at 553nm, indicating atypical heme-binding mode of euglena cytochrome c__-_1 as found in Euglena cytochrome c_<553>. The N-terminal sequence studies of the c__-_1 polypeptide showed that the first cysteine residue was replace by phenylalanine and the heme-c was bound to a cysteine through only a single thioether bond.
3. A cDNA corresponding to cytochrome c<@D5-@>D5<@D21@>D1 polypeptide was isolated and its total seq=uence was determined to deduce the amino acid sequence of Euglena cytochrome <@D5-@>D5<@D21@>D2. The mature protein was composed of 243 amino acids and the replacement mentioned above was confirmed. Also the comparison of this sequence with others revealed the functionally important regions commonly found in cytochromes c<@D5-@>D5<@D21@>D2.
4. Using gene engineering technique the important regions for function and assembly of yeast cytochrome c__-_1 were identified. (continues to a separate page)
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