Amino-acid sequence of cytochrome c-553 from Desulfovibrio desulfuricans Norway.

The amino-acid sequence of the cytochrome c-553 from Desulfovibrio desulfuricans Norway has been determined and compared with that of two different cytochromes c-553 from D. vulgaris already described and with that cytochrome c-551 from Pseudomonas. This low-molecular-weight monohemic cytochrome comprises 80 amino acids and has the typical characteristics of small cytochromes such as mitochondrial cytochromes. Secondary-structure predictions are deduced from sequence data and are compared with X-ray three-dimensional structures of low-molecular-weight cytochrome c. The phylogenetic situation of Desulfovibrio cytochromes c-533 in the cytochrome c superfamily is discussed.