1993 Fiscal Year Final Research Report Summary
Control mechanisim of the electron transport in chloroplasts
| Project/Area Number |
04044110
|
|---|
| Research Category |
Grant-in-Aid for international Scientific Research
|
| Allocation Type | Single-year Grants |
|---|
| Section | Joint Research |
|---|
| Research Institution | Osaka University |
|---|
Principal Investigator |
MATSUBARA Hiroshi Osaka Univ., Fac.Sci., Dept.Biol., Professor, 理学部, 教授 (00028242)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MALKIN Richard Univ. California, Berkeley, Dept. Plant Biology, Professor, Berkeley・Dept. Plant Biol, Prof.
BUCHANAN Bob.b. Univ. California, Berkeley, Dept. Plant Biology, Professor, Berkeley・Dept. Plant Biol, Prof.
OH-OKA Hirozo Osaka Univ., Fac.Sci., Dept.Biol., Associate Researcher, 理学部, 助手 (30201966)
SAEKI Kazuhiko Osaka Univ., Fac.Sci., Dept.Biol., Associate Researcher, 理学部, 助手 (40201511)
WADA Keishiro Kanazawa Univ., Fac.Sci., Dept.Biol., Professor, 理学部, 教授 (70028174)
|
|---|
| Project Period (FY) |
1992 – 1993
|
| Keywords | ferredoxin / iron-sulfur cluster / Green sulfur bacteria / reaction center / FNR / isoenzyme / thioredoxin / Rieske protein |
|---|
| Research Abstract |
Saeki et al. have constructed mutated fdxN of R. capsulatus with gene-engineering techniques. They identified cysteine residues essential to activity. With EPR spectroscopy, the spin interaction was found to be strongly affected by the amino acid residues around Fe-S clusters. He also demonstrated that the structures of fdxA product around [3Fe-4S] cluster and carboxyl terminal region were important to function physiologically.
Oh-oka et al. have succeeded in purifying the Chlorobium reaction center complex (CRC-2) made of two subunits, that is, the core protein (68kDa) and cytochrome c551(21kDa), respectively. Laser flash photolysis revealed the primary charge separation, followed by the delayed fluorescence concomitant with the formation of P840^T. They also have cloned the cytochrome c551 gene, and intend to construct transformation system in Chlorobium.
Wada have isolated two FNR isoenzymes from radish leaf and root. Antibodies against them were raised in rabbits. Each antibody showed specific reactivity and had no cross-reactivity. The antibodies distinguished the enzyme forms from roots and leaves of radish as well as other flowering plants. The FNR isoenzymes showed organ-specific distribution.
Buchanan reported that the level of thioredoxin in the endosperm might be under hormonal control during germination. He also demonstrated that spinach thioredoxin m inhibits DNA synthesis in fertilized Xenopus eggs.
Malkin have recently cloned the petC, which encoded Rieske protein. He intends to construct site-directed mutagenesis of the petC in order to study the cyclic electron transport with EPR technique.
|
