Distribution of the rubredoxin gene among the Clostridium butyricum species.

With PCR methods, the rubredoxin gene was systematically identified among 11 strains of Clostridium butyricum; this ubiquity means major functions in the metabolism of the Clostridia. The 11 PCR products allowed deduction of a sequence of 26 amino acids corresponding to positions 11-36 of the rubredoxin. They all contained the tyrosines at positions 11 and 13 and the phenylalanine at position 30 characteristic of the rubredoxin, but differed at positions 14-17, 20, 25, 29, and 31, allowing determination of three types of rubredoxins among these 11 strains of C. butyricum.