The Alternative Route to Heme in the Methanogenic Archaeon Methanosarcina barkeri

Figure 5

AhbC from M. barkeri generates iron-coproporphyrin III in vivo. The HPLC analysis of cell free extracts from E. coli cells producing recombinant CysG and recombinant AhbAB, AhbC, and AhbD from M. barkeri (upper panel) showed the accumulation of iron-coproporphyrin III (Fe-COPRO III). In E. coli cells producing recombinant CysG together with recombinant AhbAB and AhbC the formation of Fe-COPRO III was also observed (second panel). In contrast, the coproduction of CysG with AhbAB and AhbD did not result in the formation of Fe-COPRO III (third panel). The chromatographic behavior of the Fe-COPRO III standard is shown in the lower panel.