MOLECULAR-CLONING AND SEQUENCING OF CYTOCHROME C' FROM THE PHOTOTROPHIC PURPLE SULFUR BACTERIUM CHROMATIUM-VINOSUM

The gene for cytochrome c' from Chromatium vinosum was cloned from a H indIII-SalI digest of genomic DNA. A 1.4 kbp fragment containing the g ene was sequenced in both directions using the Sanger dideoxy method. The cytochrome c' gene codes for a 154-residue peptide, of which the l ast 131 amino acids match the previously determined sequence of the pr otein. The remaining 23 residues represent a signal sequence that is c leaved from the polypeptide upon translocation to the periplasmic spac e. An additional open reading frame on the other strand of the fragmen t codes for a peptide that contains four regions that are homologous t o corresponding regions of the cytochrome b-type subunit of several Ni -Fe hydrogenases.