Figure 3
Crystal structure of Sac-KARI. (A) A dimer comprising the asymmetric unit is shown as a ribbon model with the monomers coloured green and cyan. The N and C termini are indicated, as are the Rossmann and knot domains and a few secondary structural elements of interest, which are coloured yellow. The bound sulphate and magnesium ions are shown as stick-and-sphere models. (B) The second sulphate interacts with the β2-αB loop. It can form hydrogen bonds with R49 and S53, as does the 2′-phosphate of NADPH. (C) Magnesium binding. The bound magnesium ion is shown as a purple sphere. The surrounding acidic side chains are shown as stick models. D191 is from the second monomer, which is coloured cyan rather than green.
