Single-molecule studies reveal the off-pathway elemental pause state as a target of streptolydigin inhibition of RNA polymerase and its dramatic enhancement by Gre factors.
bioRxiv
; 2023 Jun 05.
Article
en En
| MEDLINE
| ID: mdl-37333075
ABSTRACT
Antibiotic streptolydigin (Stl) inhibits bacterial transcription by blocking the trigger loop folding in the active center of RNA polymerase (RNAP), which is essential for catalysis. We use acoustic force spectroscopy to characterize the dynamics of transcription elongation in ternary elongation complexes of RNAP (ECs) in the presence of Stl at a single-molecule level. We found that Stl induces long-lived stochastic pauses while the instantaneous velocity of transcription between the pauses is unaffected. Stl enhances the short-lived pauses associated with an off-pathway elemental paused state of the RNAP nucleotide addition cycle. Unexpectedly, we found that transcript cleavage factors GreA and GreB, which were thought to be Stl competitors, do not alleviate the streptolydigin-induced pausing; instead, they synergistically increase transcription inhibition by Stl. This is the first known instance of a transcriptional factor enhancing antibiotic activity. We propose a structural model of the EC-Gre-Stl complex that explains the observed Stl activities and provides insight into possible cooperative action of secondary channel factors and other antibiotics binding at the Stl-pocket. These results offer a new strategy for high-throughput screening for prospective antibacterial agents.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
BioRxiv
Año:
2023
Tipo del documento:
Article
País de afiliación:
Rusia