FIGURE 4.

Ligand switching associated with a change in redox state of Rev-erbβ LBD. A, EPR spectroscopic analysis of heme complexes with the reduced (Red) and oxidized (Ox) proteins (complexes were prepared at a ratio of 1:1.5 of Fe³⁺-heme:LBD). B, EPR analysis of E. coli cells overexpressing Rev-erbβ LBD (without or with oxidation by 30 mm diamide (DA) for 4 and 8 h). Inset, Western blot analysis of the EPR samples from the diamide treatment at 0, 4, and 8 h using anti-pentahistidine antibody. C, EPR analysis of C384A-heme and C374S-heme complexes as in A. Note that the in vitro experiments were performed in Buffer B. The minor peaks at g values of 2.0 and 1.99 are from the buffer.