Fig. 5.

Kang A contacts with wild-type and Rif^R RNAP. Schematic summary of the Kang A/RNAP β subunit contacts. Residues that make only nonpolar contacts are shown as labels with arcs denoting the contacts. The side chains (or main chain atoms for F430) of residues that make polar contacts are shown in stick format (H-bonds, gray dashed lines; cation-π interactions, red dashed lines). The color-coding of residues/residue labels is as follows: residues that contact the Rif scaffold in the Rif/RNAP structure, cyan; residues that also make nonpolar contacts with K-sugar, yellow arc; residues that contact K-sugar but do not contact the Rif scaffold, yellow. R604 (colored violet) makes a cation-π interaction with the Rif scaffold but also makes a salt bridge with K-acid. Residues that confer Rif^R when substituted are denoted by colored boxes as in (A). Residues that lose contacts with Kang A in the Rif^R S447L RNAP mutant are denoted by red background shading