Expression of C. acetobutylicium FabZ and FabF1 in E. coli. Panel A. Expression of C. acetobutylicium FabF1 and FabZ from their native coding sequences was induced in E. coli BL21(DE3) under control of a phage T7 promoter. Lane: 1, molecular mass markers; lane 2, proteins expressed in the presence of vector pET28b; lane 3, proteins expressed in the presence of pHW28 (FabF1) and lane 4, proteins expressed in the presence of pHW39 (FabZ). Panel B. An expression plasmid encoding the codon-optimized C. acetobutylicium fabZ was introduced into E. coli BL21 (DE3). Lane: 1, molecular mass markers; lane 2, plasmid pHW74 which expresses native fabZ; lane 3, plasmid pHW74m which expresses the codon-optimized fabZ; lane 4, FabZ expressed from the codon-optimized gene purified by nickel-chelate chromatography and lane 5, FabF1 purified by nickel-chelate chromatography.