SNAP annotations: PDB entry 7xui

PDB-id

7xui; DSSR-derived features in text and JSON formats; DNAproDB

Class

transcription

Method

cryo-EM (3.61 Å)

Summary

cryo-EM structure of sigma70 bound hk022 putrna-associated e.coli RNA polymerase elongation complex

Reference

Hwang S, Olinares PDB, Lee J, Kim J, Chait BT, King RA, Kang JY (2022): "Structural basis of transcriptional regulation by a nascent RNA element, HK022 putRNA." Nat Commun, 13, 4668. doi: 10.1038/s41467-022-32315-y.

Abstract

Transcription, in which RNA polymerases (RNAPs) produce RNA from DNA, is the first step of gene expression. As such, it is highly regulated either by trans-elements like protein factors and/or by cis-elements like specific sequences on the DNA. Lambdoid phage HK022 contains a cis-element, put, which suppresses pausing and termination during transcription of the early phage genes. The putRNA transcript solely performs the anti-pausing/termination activities by interacting directly with the E.coli RNAP elongation complex (EC) by an unknown structural mechanism. In this study, we reconstituted putRNA-associated ECs and determined the structures using cryo-electron microscopy. The determined structures of putRNA-associated EC, putRNA-absent EC, and σ₇₀-bound EC suggest that the putRNA interaction with the EC counteracts swiveling, a conformational change previously identified to promote pausing and σ₇₀ might modulate putRNA folding via σ₇₀-dependent pausing during elongation.