PDBsum entry 2wnm

Hydrolase

PDB id: 2wnm

Contents

Protein chain

59 a.a. *

* Residue conservation analysis

PDB id:

2wnm

Name:

Hydrolase

Title:

Solution structure of gp2

Structure:

Gene 2. Chain: a. Synonym: gp2. Engineered: yes

Source:

Enterobacteria phage t7. Organism_taxid: 10760. Expressed in: escherichia coli. Expression_system_taxid: 562.

NMR struc:

1 models

Authors:

B.Camara,M.Liu,A.Shadrinc,B.Liu,P.Simpson,R.Weinzierl,K.Severinovc, E.Cota,S.Matthews,S.R.Wigneshweraraj

Key ref:

B.Cámara et al. (2010). T7 phage protein Gp2 inhibits the Escherichia coli RNA polymerase by antagonizing stable DNA strand separation near the transcription start site. Proc Natl Acad Sci U S A, 107, 2247-2252. PubMed id: 20133868

Date:

13-Jul-09 Release date: 16-Feb-10

Protein chain

P03704  (VRPI_BPT7) -  Bacterial RNA polymerase inhibitor from Escherichia phage T7

Seq: 64 a.a.

Struc: 59 a.a.

Enzyme reactions

• Enzyme class: E.C.?

Proc Natl Acad Sci U S A 107:2247-2252 (2010)

PubMed id: 20133868

T7 phage protein Gp2 inhibits the Escherichia coli RNA polymerase by antagonizing stable DNA strand separation near the transcription start site.

B.Cámara, M.Liu, J.Reynolds, A.Shadrin, B.Liu, K.Kwok, P.Simpson, R.Weinzierl, K.Severinov, E.Cota, S.Matthews, S.R.Wigneshweraraj.

ABSTRACT

Infection of Escherichia coli by the T7 phage leads to rapid and selective inhibition of the host RNA polymerase (RNAP)--a multi-subunit enzyme responsible for gene transcription--by a small ( approximately 7 kDa) phage-encoded protein called Gp2. Gp2 is also a potent inhibitor of E. coli RNAP in vitro. Here we describe the first atomic resolution structure of Gp2, which reveals a distinct run of surface-exposed negatively charged amino acid residues on one side of the molecule. Our comprehensive mutagenesis data reveal that two conserved arginine residues located on the opposite side of Gp2 are important for binding to and inhibition of RNAP. Based on a structural model of the Gp2-RNAP complex, we propose that inhibition of transcription by Gp2 involves prevention of RNAP-promoter DNA interactions required for stable DNA strand separation and maintenance of the "transcription bubble" near the transcription start site, an obligatory step in the formation of a transcriptionally competent promoter complex.