Non-heme iron proteins of Desulfovibrio: the primary structure of ferredoxin I from Desulfovibrio africanus.

Three different ferredoxins have been isolated from the sulfate reducing bacterium, Desulfovibrio africanus. The present paper describes the complete amino acid sequence of D. africanus ferredoxin I. This sequence was determined using automatic protein sequencing in liquid phase and in solid phase. The 61 amino acid residues of the sequence have been aligned with the aid of peptides obtained by cyanogen bromide, cleavage and by tryptic hydrolysis. This ferredoxin which contains 4 cysteine residues represents the most simple case of one (4 Fe-4 S) cluster ferredoxin. A comparison of D. africanus ferredoxin I with D. gigas and Clostridium pasteurianum ferredoxins is presented in terms of structural and possible evolutionary relationships.