National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
2-R01 GM114450
米国
引用
ジャーナル: Proc Natl Acad Sci U S A / 年: 2020 タイトル: The antibiotic sorangicin A inhibits promoter DNA unwinding in a rifampicin-resistant RNA polymerase. 著者: Mirjana Lilic / James Chen / Hande Boyaci / Nathaniel Braffman / Elizabeth A Hubin / Jennifer Herrmann / Rolf Müller / Rachel Mooney / Robert Landick / Seth A Darst / Elizabeth A Campbell / 要旨: Rifampicin (Rif) is a first-line therapeutic used to treat the infectious disease tuberculosis (TB), which is caused by the pathogen (). The emergence of Rif-resistant (Rif) presents a need for new ...Rifampicin (Rif) is a first-line therapeutic used to treat the infectious disease tuberculosis (TB), which is caused by the pathogen (). The emergence of Rif-resistant (Rif) presents a need for new antibiotics. Rif targets the enzyme RNA polymerase (RNAP). Sorangicin A (Sor) is an unrelated inhibitor that binds in the Rif-binding pocket of RNAP. Sor inhibits a subset of Rif RNAPs, including the most prevalent clinical Rif RNAP substitution found in infected patients (S456>L of the β subunit). Here, we present structural and biochemical data demonstrating that Sor inhibits the wild-type RNAP by a similar mechanism as Rif: by preventing the translocation of very short RNAs. By contrast, Sor inhibits the Rif S456L enzyme at an earlier step, preventing the transition of a partially unwound promoter DNA intermediate to the fully opened DNA and blocking the template-strand DNA from reaching the active site in the RNAP catalytic center. By defining template-strand blocking as a mechanism for inhibition, we provide a mechanistic drug target in RNAP. Our finding that Sor inhibits the wild-type and mutant RNAPs through different mechanisms prompts future considerations for designing antibiotics against resistant targets. Also, we show that Sor has a better pharmacokinetic profile than Rif, making it a suitable starting molecule to design drugs to be used for the treatment of TB patients with comorbidities who require multiple medications.