Figure 6.
c-di-GMP Is Required for BldD CTD Dimerization in Solution
(A) DSS chemical crosslinking. We crosslinked 10 μM His6-BldD-DBD (10.7 kDa) or His6-BldD-CTD (12.0 kDa) by using 1 mM DSS in the presence or absence of 20 μM c-di-GMP as indicated. In control reactions, the DSS solvent dimethylsulfoxide (DMSO) alone was added to the proteins. Samples were analyzed by SDS-PAGE. Monomers and dimers of each BldD domain are marked by arrows.
(B) SEC analysis of the WT BldD CTD and BldD CTD DGR-X8-DQDR mutant in the presence of 3 μM c-di-GMP. The WT CTD + c-di-GMP is dimeric, while the quadruple mutant is monomeric. The standard curve was determined using cytochrome C (12 kDa), carbonic anhydrase (29 kDa), and albumin (66 kDa) (green circles).