Figure 2

Structure of dalfopristin and quinupristin within the PTC. To facilitate visualization of the interactions of dalfopristin and quinupristin with 23S rRNA, rRNA bases not involved in binding have been omitted. (A) Local environment of dalfopristin (in orange). A2062 is highlighted in purple; nucleotides, which are interacting through hydrogen bonds with either dalfopristin or quinupristin, are shown in dark blue. (B) Local environment of quinupristin (in green). Colours are as in (A). (C) Stereo view of the electron density map of quinupristin (in green) and dalfopristin (in orange). Both compounds have been omitted during calculation of the sigmaA weighted difference map, which is contoured at 1.5σ. (D) Stereo representation of dalfopristin and quinupristin and their local environment. Colours as in (A).