Extended Data Fig. 5: Heme binding properties of CydDCwt and CydDCH85A.
From: Dissecting the conformational complexity and mechanism of a bacterial heme transporter
(a) Size exclusion chromatograms (SEC) of CydDC (wt) in the absence and presence of exogenously added heme (applied before the experiment). Wild-type CydDC contains bound heme from native source, which co-migrates with the peak fraction of the protein. Addition of extra heme increases the intensity of the A410 signal indicating greater heme occupancy. (b) SEC of CydDCH85A in the absence and presence of exogenous heme (applied before the experiment). The chromatograms show that native heme does not copurify with the mutant variant CydDCH85A. Furthermore, adding exogenous heme does not have the same effect observed with the wild-type CydDC. The slight increase in the A410 signal is attributed to heme molecules migrating into hydrophobic regions of detergent micelles. Relative ratios of the peak intensities between A410 (heme component) and A280 (protein component) are given. (c) Relative change of TM in the absence and presence of exogenously added heme molecules to purified samples of CydDCwt and CydDCH85A. Data are presented as mean values ±s.d. (n = 3 assay technical replicates).
