Figure 3.
AhbAB from M. barkeri is a heme binding heterodimeric complex. (a) SDS-PAGE analysis of the purified AhbAB complex after copurification of His6-tagged AhbA with nontagged AhbB on Ni-NTA agarose. The M r values of the marker proteins are indicated. (b) UV-visible absorption spectra of purified AhbAB in the oxidized form (as isolated, solid line) and the dithionite-reduced state (dashed line). (c) HPLC analysis of extracted tetrapyrroles of AhbAB. The comparison of the retention time of the extracted tetrapyrrole (upper panel) with a hemin standard (lower panel) suggests the presence of heme in purified AhbAB.