Figure 3.

Rv2971 substrate and cofactor binding pocket architecture. Cartoon representation of (a) the substrate binding pocket and (b) the NADPH binding pocket. Two malonate ions and a single chloride ion bound during crystallization are represented as cyan sticks and magenta spheres, respectively. Electron density of maps is shown as F _o − F _c simulated-annealing OMIT maps contoured at 3σ. Amino-acid residues involved in binding to the malonate and chloride ions are represented as green sticks. Hydrogen-bond formation between contact residues and ions is represented as black dashes, with bond distances ranging between 2.6 and 3.6 Å. The Asp52-Tyr57-Lys82-His115 catalytic tetrad is represented in wheat. The solvent-accessible surface representation coloured by electrostatic potential of the (c) substrate binding pocket and (d) NADPH binding pocket was calculated by APBS (Baker et al., 2001 ▶). The potential contours are shown on a scale from +5.0 (blue) to −5.0 k _B T e⁻¹ (red); white indicates a value close to 0 k _B T e⁻¹. Indicated are the positions of the Asp52-Tyr57-Lys82-His115 catalytic tetrad.