Figure 7.

Surface conservation and the dimer interface in Syn6301-PRK. (a) Surface conservation in the Syn6301-PRK protomer. Three perpendicular views are shown. Chain A is shown in surface representation, with the residue-similarity score from an alignment of class IA PRK sequences depicted as a colour gradient from cyan to magenta, indicating increasing sequence conservation. The active-site cleft is indicated. Chain B is shown in ribbon representation; disulfide bonds are shown as red sticks. (b) Detailed view of the dimer interface in Syn6301-PRK. The region that is boxed in (a) is magnified. The left panel shows the surface conservation in chain A and key contact residues in chain B highlighted in stick representation. The right panel shows the hydrogen-bond network at the dimer interface. Key contact residues are indicated and shown in stick representation. Putative hydrogen bonds are represented as dotted lines. The Cys229–Cys235 disulfide bond is depicted as red sticks. Secondary-structure elements and loops involved in the dimer interaction are indicated. The position of the local twofold symmetry axis is indicated.