Cloning, sequencing and expression of the tetraheme cytochrome c(3) from Desulfovibrio gigas

The gene encoding the tetraheme cytochrome c(3) from Desulfovibrio gigas wa s cloned and sequenced from a 2.7-kb EcoRI-PstI insert of D. gigas DNA. The derived amino acid sequence showed that the D. gigas cytochrome c3 is synt hesized as a precursor protein with an N-terminal signal peptide sequence o f 25 residues and allowed the correction of the previous reported amino aci d sequence (Matias et al. Protein Science 5 (1996) 1342-1354). Expression i n D. vulgaris (Hildenborough) was possible by conjugal transfer of a recomb inant broad-host-range vector pSUP104 containing a SmaI fragment of the D. gigas cytochrome c(3) gene. Biochemical, immunological and spectroscopic an alysis of the purified protein showed that the recombinant cytochrome is id entical to that isolated from D. gigas. (C) 2000 Elsevier Science B.V. All rights reserved.