Pseudouridimycin and Rifampin (image) Rutgers University Share Print E-Mail Caption Structure of bacterial RNA polymerase, showing the binding sites for the new antibiotic pseudouridimycin (PUM) and the current antibacterial drug rifampin (Rif). PUM has a lower resistance rate and a smaller resistance target than Rif -- just 2 to 4 positions where alterations that result in PUM-resistance (blue) vs. 27 positions where alterations result in Rif-resistance (red) -- due to functional constraints on alteration of the binding site for PUM in the RNA polymerase active center. Credit David Degen and Richard H. Ebright (Rutgers University) Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.