Fig. 2. Characterization of the RirA iron–sulfur cluster. (A) UV-visible absorbance and (B) CD spectra of reconstituted RirA (371 μM [4Fe–4S] RirA) in buffer B. Pathlength 1 mm. (C) and (D) Positive ion mode ESI-MS deconvoluted spectra of RirA (30 μM in cluster in 250 mM ammonium acetate pH 7.32) under non-denaturing conditions in the monomer (C) and dimer (D) mass regions.
