Primary structure of the assimilatory-type sulfite reductase from Desulfovibrio vulgaris (Hildenborough): cloning and nucleotide sequence of the reductase gene.

The nucleotide sequence encoding the structural gene (651 bp) and flanking regions for the assimilatory-type sulfite reductase from the sulfate-reducing bacterium Desulfovibrio vulgaris (Hildenborough) was determined after cloning a 1.4 kb HindIII/SalI genomic fragment possessing the gene into Bluescript pBS(+)KS. The primary structure of the protein was deduced, and the molecular mass of the apoprotein was estimated as 24 kDa. The amino acid sequence of the polypeptide shows some similarities at putative [Fe4S4] cluster binding sites in comparison with the heme protein subunit of the larger Escherichia coli and Salmonella typhimurium sulfite reductases and spinach nitrite reductase. This is the first reported sequence of a member of a new class of low molecular weight assimilatory sulfite-reducing enzymes recently identified in a number of anaerobic bacteria [Moura, I., Lina, A. R., Moura, J. J. G., Xavier, A. V., Fauque, G., Peck, H. D., & Le Gall, J. (1986) Biochem. Biophys. Res. Commun. 141, 1032-1041].