Escherichia coli is able to produce heterologous tetraheme cytochrome c(3)when the ccm genes are co-expressed

The production of Desulfovibrio vulgaris Hildenborough cytochrome c(3) (M-r 13 000), which is a tetraheme cytochrome, in Escherichia coli was examined . This cytochrome was successfully produced in an E. coli strain co-express ing the ccmABCDEFGH genes involved in the cytochrome c maturation process. The apocytochrome c(3) was matured in either anaerobic or aerobic condition s, but aerobic growth in the presence of delta-aminolevulinic acid was foun d to be best for cytochrome c(3) production. Site-directed mutagenesis was performed to investigate the effect of the presence of four amino acids in between the two cysteines of the heme binding sites 2 and 4 on the maturati on of holocytochrome c(3) in E. coli. (C) 2000 Elsevier Science B.V. All ri ghts reserved.