Primary structure of a high potential, four-iron-sulfur ferredoxin from the photosynthetic bacterium Rhodospirillum tenue.

The amino acid sequence of a high oxidation-reduction potential iron-sulfur protein (HiPIP) isolated from the purple photosynthetic bacterium Rhodospirillum tenue has been determined. This is the smallest of the HiPIP's, containing 63 residues, with only 3 residues apparently conserved in addition to the 4 cluster-binding cysteines. A minimum of four internal genetic gaps is postulated to align tenue high potential iron-sulfur protein with the previously known proteins. It is the most divergent of its class, with an average of only 25% identically matching residues in common with any of the other species.