Chlorobium limicola, cytochromes

In Chlorobium limicola . thiosulfatophilum cytochrome c-SSl serves as electron acceptor of thiosulfate oxidation, before the electrons flow to oxidized bacteriochlorophyll via a soluble small cytochrome c-SSS and a membrane-bound cytochrome (2). The absence of cytochrome c-SSl in the non-thiosulfate-utilizing Chlorobiaceae might be one explanation why these organisms cannot use thiosulfate (4). 

FI Oh-oka, S Kakutani, FI Matsubara, R Malkin and S Itoh (1993) Isolation of the photoactive reaction center complex that contains three types ofFe-S centers and a cytochrome c subunit from the green sulfur bacterium Chlorobium limicola f. thiosulfatophilum strain Larsen. Plant Cell Physiol 34 93-101... 

Cytochrome c-552 belongs to cytochrome c6 or c8 group. As the cytochromes of this group react rapidly with Pseudomonas aeruginosa nitrite reductase but does not react with cow cytochrome c oxidase (Yamanaka, 1992), their structures have been supposed to be similar to each other. Thus, their amino acid sequences resemble each other though the sequence of Chlorobium limicola f. thiosulfatophi-lum cytochrome c-555 shows smaller similarity to other cytochromes c6 or c8 than the similarities that other cytochromes c6 or c8 show each other (Table 3.2). 

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