(A) Target of Myx [11,12]. (B) Target of Cor [11,12]. (C) Target of Rip [11,12]. (D) Target of Lpm [10; D.D., R.Y.E., E.S., S.D., and R.H.E., unpublished]. Each panel shows two orthogonal views of RNAP. Red, sites of substitutions conferring moderate- to high-level resistance (≥4-fold resistance) to the specified inhibitor; blue, sites of substitutions conferring resistance to rifamycins; violet sphere, active-center Mg2+. The Myx, Cor, and Rip targets overlap essentially in toto. The Lpm target is adjacent to, but does not overlap, or only minimally overlaps, the Myx, Cor, and Rip targets (compare bottom subpanels of D to bottom subpanels of A–C).