Transcription elongation stalls at lesions in the DNA template. For the DNA lesion to be repaired, the stalled transcription elongation complex (EC) has to be removed from the damaged site. Here we show that translation, which is coupled to transcription in bacteria, actively dislodges stalled ECs from the damaged DNA template.
View Article and Find Full Text PDFAntimicrob Agents Chemother
November 2021
Rifamycins, such as rifampicin (Rif), are potent inhibitors of bacterial RNA polymerase (RNAP) and are widely used antibiotics. Rifamycin resistance is usually associated with mutations in RNAP that preclude rifamycin binding. However, some bacteria have a type of ADP-ribosyl transferases, Arr, which ADP-ribosylate rifamycin molecules, thus inactivating their antimicrobial activity.
View Article and Find Full Text PDFTranscribing RNA polymerase (RNAP) can fall into backtracking, phenomenon when the 3' end of the transcript disengages from the template DNA. Backtracking is caused by sequences of the nucleic acids or by misincorporation of erroneous nucleotides. To resume productive elongation backtracked complexes have to be resolved through hydrolysis of RNA.
View Article and Find Full Text PDFMost clinical MRSA (methicillin-resistant S. aureus) isolates exhibit low-level β-lactam resistance (oxacillin MIC 2-4 μg/ml) due to the acquisition of a novel penicillin binding protein (PBP2A), encoded by mecA. However, strains can evolve high-level resistance (oxacillin MIC ≥256 μg/ml) by an unknown mechanism.
View Article and Find Full Text PDFRNA polymerases (RNAPs) accomplish the first step of gene expression in all living organisms. However, the sequence divergence between bacterial and human RNAPs makes the bacterial RNAP a promising target for antibiotic development. The most clinically important and extensively studied class of antibiotics known to inhibit bacterial RNAP are the rifamycins.
View Article and Find Full Text PDFTranscription, the first phase of gene expression, is performed by the multi-subunit RNA polymerase (RNAP). Bacterial RNAP is a validated target for clinical antibiotics. Many natural and synthetic compounds are now known to target RNAP, inhibiting various stages of the transcription cycle.
View Article and Find Full Text PDFAntibiotic-resistant bacterial pathogens pose an urgent healthcare threat, prompting a demand for new medicines. We report the mode of action of the natural ansamycin antibiotic kanglemycin A (KglA). KglA binds bacterial RNA polymerase at the rifampicin-binding pocket but maintains potency against RNA polymerases containing rifampicin-resistant mutations.
View Article and Find Full Text PDFThe madurastatins are pentapeptide siderophores originally described as containing an unusual salicylate-capped N-terminal aziridine ring. Isolation of madurastatin C1 (1) (also designated MBJ-0034), from Actinomadura sp. DEM31376 (itself isolated from a deep sea sediment), prompted structural reevaluation of the madurastatin siderophores, in line with the recent work of Thorson and Shaaban.
View Article and Find Full Text PDFDrug-induced hepatitis (DIH) is one of the major complications among the treatment of patients with tuberculosis (TB); it might even be fatal. This study tries to address the recurrence of DIH with 2 anti-TB regimens. In the retrospective study from 2007 to 2010, 135 TB patients with DIH who were older than 16 years were entered to study.
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