Fig. 1: Native and activated DgcR dimers adopt distinct domain arrangements.
From: Activation mechanism of a small prototypic Rec-GGDEF diguanylate cyclase
a DgcR domain organisation with important features and residues highlighted. The Rec and the GGDEF domains are linked by the extension (orange) of the C-terminal Rec helix. Red and yellow bars indicate the DxLT and GGDEF motif, respectively. b, c Side and top views of DgcR’ (c) and DgcR’* (d) dimers. Within one protomer, domains and important elements are highlighted by colour. The C-terminal Rec helix (α5) is coloured in gold, the wide turn in red, the N-terminal GGDEF helix (α0’) in cyan and the characteristic β-hairpin (with GGEEF sequence) in yellow. The BeF3- modified aspartates of the Rec domains, the bound Mg ++ ions (green), and the 3’dGTP substrate analogues bound to the GGDEF active sites are shown in full. In both cases, the Rec domains obey twofold symmetry. The GGDEF domains are related by twofold symmetry (with the two 3’dGTP ligands opposing each other) only in DgcR’*, while in DgcR’ they are related by ~90°.
