Figure 7

Structural analysis of SahH and its major phosphorylation sites.

(A) Cartoon representation of Mtb-SahH bound to NAD⁺ cofactor. Both the domains of SahH have been labeled. Thr219–Thr221 residues have been colored (magenta) to mark their proximity with NAD⁺ (purple). Other color representations are: helix (cyan), strand (yellow) and turn (red). (B) Region depicting interaction of NAD⁺ (green) with Thr219–Thr221. Side chains of Thr residues are shown in orange color. Distances of side-chain oxygen of Thr residues from oxygen of NAD⁺ are: 2.855 Å (Thr219), 4.239 Å (Thr220) and 3.155 Å (Thr221). Other color representations are according to that in (A). (C) and (D) Stick diagram representation of Thr219–Thr221 residues with NAD⁺. Side-chain oxygen molecules of Thr residues were modified to attach a phosphate group with two negative charges in (D). Color representations are as follows: Thr219–Thr221 (red), NAD⁺ (green), Phosphorus (yellow) and Oxygen (white).