Fig. 5: Possible alternate conformations sampled by LetA.
From: LetA defines a structurally distinct transporter family
a, Cryo-EM structure of LetA (left) and AlphaFold model 149 (right) with TM3 helices coloured. b, Visualization of changes in Cα positions between the cryo-EM structure and AlphaFold model 149. The model on the left is oriented as in panel a, but omitted for clarity; vectors indicate the displacement of Cα positions between the cryo-EM structure and AlphaFold model 149. Models are aligned on TMDN. The black arrows indicate the direction of domain movement in model 149 relative to the cryo-EM structure. c, Molecular surfaces of the LetA cryo-EM structure and AlphaFold model 149, coloured by electrostatic potential. d, Cryo-EM LetA structure and AlphaFold model 149, with residues L94, I383 (red) and Q180, R380 (blue) shown as spheres. The Cβ distances (dashed lines) are shown for the pairs of residues that are mutated to cysteine. e, Representative western blot of a crosslinking experiment to probe the LetA conformations observed in the cryo-EM structure and AlphaFold model 149, as shown in panel d. Samples were treated with either DMSO (3%, control) or BMOE (1 mM) and subjected to western blotting using anti-LetA antibody (clone 72). Successful crosslinking results in a heterodimeric product with an apparent molecular weight of approximately 35 kDa. Gel source data are provided in Supplementary Fig. 1o. f, Quantification of western blots from the LetA Cys crosslinking assay, including the blot from panel e, as well as two additional biological replicates (n = 3 total). The bar graph shows the fold increase in the crosslinked heterodimeric product upon treatment with the BMOE crosslinker relative to the corresponding uncrosslinked control.
