PDBsum entry 4lup

Transcription/DNA

PDB id: 4lup

Contents

Protein chains

91 a.a.

DNA/RNA

Ligands

EDO

Waters ×207

PDB id:

4lup

Name:

Transcription/DNA

Title:

Crystal structure of the complex formed by region of e. Coli sigmae bound to its -10 element non template strand

Structure:

RNA polymerase sigma factor. Chain: a, c. Fragment: unp residues 3-92. Engineered: yes. Region 2 of sigmae of e. Coli. Chain: b, d. Engineered: yes

Source:

Escherichia coli. Organism_taxid: 562. Gene: rpoe, bn17_18601, ecs3439, lf82_1962. Expressed in: escherichia coli. Expression_system_taxid: 562. Synthetic: yes. Other_details: oligonucleotide synthetically generated

Resolution:

1.20Å R-factor: 0.147 R-free: 0.165

Authors:

S.Campagne,M.E.Marsh,J.A.V.Vorholt,F.H.-T.Allain,G.Capitani

Key ref:

S.Campagne et al. (2014). Structural basis for -10 promoter element melting by environmentally induced sigma factors. Nat Struct Biol, 21, 269-276. PubMed id: 24531660 DOI: 10.1038/nsmb.2777

Date:

25-Jul-13 Release date: 19-Feb-14

Protein chains

Q0P6M2  (Q0P6M2_ECOLX) -  RNA polymerase sigma factor from Escherichia coli

Seq: 191 a.a.

Struc: 91 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

DNA/RNA chains

T-G-T-C-A-A-A 7 bases

G-T-C-A-A-A 6 bases

DOI no: 10.1038/nsmb.2777

Nat Struct Biol 21:269-276 (2014)

PubMed id: 24531660

Structural basis for -10 promoter element melting by environmentally induced sigma factors.

S.Campagne, M.E.Marsh, G.Capitani, J.A.Vorholt, F.H.Allain.

ABSTRACT

Bacterial transcription is controlled by sigma factors, the RNA polymerase subunits that act as initiation factors. Although a single housekeeping sigma factor enables transcription from thousands of promoters, environmentally induced sigma factors redirect gene expression toward small regulons to carry out focused responses. Using structural and functional analyses, we determined the molecular basis of -10 promoter element recognition by Escherichia coli σ(E), which revealed an unprecedented way to achieve promoter melting. Group IV sigma factors induced strand separation at the -10 element by flipping out a single nucleotide from the nontemplate-strand DNA base stack. Unambiguous selection of this critical base was driven by a dynamic protein loop, which can be substituted to modify specificity of promoter recognition. This mechanism of promoter melting explains the increased promoter-selection stringency of environmentally induced sigma factors.