Extended Data Fig. 10: Map and model of the domain-swapped region and crosslinking experiments to validate the domain-swapped assembly.
From: Structural basis for inhibition and regulation of a chitin synthase from Candida albicans
a-b, Unsharpened map of the domain-swapped region of UDP-GlcNAc bound CaChs2 shown at threshold 0.00475, viewed from two orientations. c. Representative density of the domain-swapped region. The protein model is shown as cartoon and side chains are shown as sticks. Some of the side chains are not built due to lack of signal. d. CaChs2 viewed from the intracellular side. The Cα atom of P906 and N917, which define the N and C-terminus of the loop between H10 and TM5, are shown as spheres. The distances from the Cα of P906 to that of N917 within the same monomer or in different monomers are labeled with dashed lines. It is noteworthy that the distance between P906 and N917 is closer in the domain swapped arrangement (30 Å) than the non-domain swapped arrangement (46.5 Å). Because the length of an amino acid in a linear chain is ~3.5 Å, non-domain swapped configuration is physically impossible. e. Model of CaChs2 dimer with one protomer in blue and the other in salmon. Cα atoms of residues where cysteine was introduced are shown as spheres. The crosslinking cysteine pairs are labeled with dashed lines. f. SDS-PAGE analysis of single and double cysteine mutants of CaChs2. The experiment has been repeated four times from two biological repeats with essentially the same results. Uncropped gel images for f are available as source data.
