PDBsum entry 3d9b

Transport protein

PDB id: 3d9b

Contents

Protein chain

1045 a.a. *

Metals

_NI

* Residue conservation analysis

PDB id:

3d9b

Name:

Transport protein

Title:

Symmetric structure of e. Coli acrb

Structure:

Acriflavine resistance protein b. Chain: a

Source:

Escherichia coli. Organism_taxid: 469008. Strain: bl21(de3)

Resolution:

3.42Å R-factor: 0.291 R-free: 0.355

Authors:

D.Veesler,S.Blangy,C.Cambillau,G.Sciara

Key ref:

D.Veesler et al. (2008). There is a baby in the bath water: AcrB contamination is a major problem in membrane-protein crystallization. Acta Crystallogr Sect F Struct Biol Cryst Commun, 64, 880-885. PubMed id: 18931428

Date:

27-May-08 Release date: 01-Jul-08

Protein chain

P31224  (ACRB_ECOLI) -  Multidrug efflux pump subunit AcrB from Escherichia coli (strain K12)

Seq: 1049 a.a.

Struc: 1045 a.a.

Acta Crystallogr Sect F Struct Biol Cryst Commun 64:880-885 (2008)

PubMed id: 18931428

There is a baby in the bath water: AcrB contamination is a major problem in membrane-protein crystallization.

D.Veesler, S.Blangy, C.Cambillau, G.Sciara.

ABSTRACT

In the course of a crystallographic study of the Methanosarcina mazei CorA transporter, the membrane protein was obtained with at least 95% purity and was submitted to crystallization trials. Small crystals (<100 microm) were grown that diffracted to 3.42 A resolution and belonged to space group R32, with unit-cell parameters a = b = 145.74, c = 514.0 A. After molecular-replacement attempts using available CorA structures as search models failed to yield a solution, it was discovered that the crystals consisted of an Escherichia coli contaminating protein, acriflavine resistance protein B (AcrB), that was present at less than 5% in the protein preparations. AcrB contamination is a major problem when expressing membrane proteins in E. coli since it binds naturally to immobilized metal-ion affinity chromatography (IMAC) resins. Here, the structure is compared with previously deposited AcrB structures and strategies are proposed to avoid this contamination.