Cofactor-mediated conformational remodeling of bmAANAT3 monitored by NMR.

(A) acetyl-CoA induced CSPs mapped on the model of bmAANAT3. (B) CSPs as a function of primary sequence for the interaction of bmAANAT3 with acetyl-CoA (green) and CoA (cyan). CSPs greater than the mean or one SD above the mean are marked by continuous and broken lines, respectively. The conserved motifs of the GNAT superfamily are indicated on the left. Black bars in the acetyl-CoA portion of the plot mark G135 and G137 which are absent in the free state of the enzyme, but tentatively assigned in the bound state. Red bars in the CoA portion of the plot mark residues that become broadened beyond detection in the CoA-bound state. (C) CoA induced CSPs mapped on the model of bmAANAT3. In (A) and (C) the white region in the three-color gradient corresponds to the mean CSP, while the magenta region to greater than mean + σ. Residues highlighted in orange in (C) highlight residues that broaden beyond detection in the presence of CoA. The position of acetyl-CoA is highlighted in green, after aligning the bmAANAT3 model with the structure of acetyl-CoA-bound DAT. Residues that experience significant CSPs for acetyl-CoA and CoA are listed in (A), while, signals that broaden (beyond detection) upon CoA binding are listed in (C).