Figure 7.

Mössbauer spectrum of SkfB. The spectrum of a sample of SkfB reconstituted with ⁵⁷Fe (vertical bars) was recorded with the sample kept at 4.2 K in a 53-mT magnetic field applied parallel to the γ-beam. The solid line overlaid with the data is a simulation with two quadrupole doublets using parameters quoted in the text. The individual contributions of the quadrupole doublets associated with the [2Fe-2S]²⁺ and [4Fe-4S]²⁺ clusters are shown as dashed and solid lines above the data, respectively. RCN, reconstituted.