Fig. 5: Detection of metal binding induced conformational changes of BbZIP using cysteine accessibility assay.
From: Molecular insights into substrate translocation in an elevator-type metal transporter
A Illustration of cysteine labeling with NEM or mPEG5k when BbZIP is in the IFC or OFC. The scaffold domain and transport domain are colored in blue and green, respectively. B Cysteine accessibility assay of the variants in the presence or absence of metal substrates (50 µM). The membrane fractions of the E.coli cells expressing the variants were treated with the indicated amounts of NEM under native conditions, followed by the treatment of mPEG5k under denaturing conditions. At least three independent experiments were conducted with similar results. C Cd content determined by ICP-MS after the treatment of the Cd-bound proteins (wild-type BbZIP and the H149A/H151A variant) in a Cd-free solution (Fig. 2C) with excess zinc ions (250 µM). The Cd/protein molar ratios from two independent experiments are shown as rhomboids.
