Highly purified photosynthetic reaction center (PscA/Cytochrome C{sub 551}){sub 2} complex of the green sulfur bacterium chlorobium limicola
- Osaka Univ. (Japan)
The photosynthetic reaction center (RC) complex that forms a homodimer of core and cytochrome c subunits was isolated form Chlorobium limicola f. thiosulfatophilum, strain Larsen. The complex showed only two subunit bands at 68 (PscA core) and 21 kDa (cytochrome c{sub 551}) on SDS-PAGE analysis, indicating the complete deletion of the light-harvesting bacteriochlorophyll {alpha} (BChl {alpha}) protein as well s the iron-sulfur protein. It contained 27 {plus_minus} 3 molecules of BChl {alpha}, 7 {plus_minus} 1 Chl-670, 3 {plus_minus} 1 carotenoids, and 1.6 {plus_minus}0.1 c-type hemes per the primary electron donor P840. The complex showed a light-induced charge separation and recombination between P840 and the acceptor Chl-670 at 77 K as follows: P840{sup *}Chl-670{r_arrow}P840{sup +}Chl-670{sup {minus}}{r_arrow}P840{sup T}Chl-670{r_arrow}P840 Chl-670. Pigment compositions and their function in the (PscA/cytochrome c{sub 551}){sub 2} complex were studied by absorption, circular dichroism, and fluorescence spectroscopy 36 refs., 8 figs.
- OSTI ID:
- 274307
- Journal Information:
- Biochemistry (Eaton), Vol. 34, Issue 40; Other Information: PBD: 10 Oct 1995
- Country of Publication:
- United States
- Language:
- English
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