SNAP output for PDB entry 6b6h [SNAP web server]

PDB-id

6b6h; SNAP-derived features in text and JSON formats; DNAproDB

Class

transcription-transferase-DNA-RNA

Method

cryo-EM (3.9 Å)

Summary

The cryo-EM structure of a bacterial class i transcription activation complex

Reference

Liu B, Hong C, Huang RK, Yu Z, Steitz TA (2017): "Structural basis of bacterial transcription activation." Science, 358, 947-951. doi: 10.1126/science.aao1923.

Abstract

In bacteria, the activation of gene transcription at many promoters is simple and only involves a single activator. The cyclic adenosine 3',5'-monophosphate receptor protein (CAP), a classic activator, is able to activate transcription independently through two different mechanisms. Understanding the class I mechanism requires an intact transcription activation complex (TAC) structure at a high resolution. Here we report a high-resolution cryo-electron microscopy structure of an intact Escherichia coli class I TAC containing a CAP dimer, a σ₇₀-RNA polymerase (RNAP) holoenzyme, a complete class I CAP-dependent promoter DNA, and a de novo synthesized RNA oligonucleotide. The structure shows how CAP wraps the upstream DNA and how the interactions recruit RNAP. Our study provides a structural basis for understanding how activators activate transcription through the class I recruitment mechanism.