FIG. 5.

Expression of E. coli cytochrome b₅₆₂ and c-b₅₆₂ polypeptides under various conditions. (A) Effects of heme and DegP on cytochrome b₅₆₂ and c-b₅₆₂ polypeptide accumulation. E. coli cytochrome b₅₆₂ or c-b₅₆₂ was expressed in either hemA strain S905 or hemA degP strain S906 grown in medium containing either 60 μM (L) or 600 μM (H) ALA. The cells also contained pEC86, which carries the ccm genes. Cell extracts were analyzed by immunoblotting using antibodies against the His tag. Thirty micrograms of protein was loaded per lane. (B) Effects of Ccm and DegP on cytochrome b₅₆₂ and c-b₅₆₂ polypeptide accumulation. E. coli cytochrome b₅₆₂ or c-b₅₆₂ was expressed in degP⁺ (Wt) strain KS272 or degP strain KS474 in either the absence or presence of the plasmid pEC86 containing the E. coli ccm genes. Proteins were analyzed as described for panel A.