<p>High-resolution crystal structures of <i>E. coli</i> NADP-IDH (EcIDH, 9ICD), <i>B. subtilis</i> NADP-IDH (BsIDH, 1HQS) and <i>A. thiooxidans</i> NAD-IDH (AtIDH, 2D4V) were downloaded from the PDB database. SmIDH structure was generated using the SWISS-MODEL modeling server, using AtIDH as a template structure. Invariant residues are highlighted by shaded blue boxes and conserved residues by open blue boxes. The conserved residues involved in the cofactor binding (▴) and substrate binding (*) are indicated. The phosphorylation site was represented by ★. The phosphorylation loop and the insert region were highlighted by shaded orange boxes. The figure was made with ESPript 2.2 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0058918#pone.0058918-Gouet1" target="_blank">[36]</a>.</p
