Structural basis of RNA-guided transcription by a dCas12f-σE-RNAP complex - PubMed
12 hours ago
- #Transcription
- #RNAP
- #CRISPR
- RNA-guided proteins play a critical role in transcriptional regulation by modulating RNA polymerase (RNAP) and its associated factors.
- Bacterial TnpB and CRISPR-associated proteins repress gene expression by blocking transcription initiation or elongation.
- A distinct class of nuclease-dead Cas12f homologues (dCas12f) activates gene expression through association with unique extracytoplasmic function sigma factors (σE).
- Cryo-electron microscopy structures reveal a new mode of RNA-guided transcription initiation by the dCas12f-σE system from Flagellimonas taeanensis.
- The study shows that CRISPR-Cas targeting largely supplants recognition of the -35 element, while the melted -10 element is stabilized through unusual stacking interactions.
- This work provides insights into an unexpected mechanism of RNA-guided transcription, expanding understanding of bacterial gene regulation and enabling programmable transcriptional control.