PDBsum entry 6fsu

Membrane protein

PDB id: 6fsu

Contents

Protein chains

388 a.a.

Waters ×53

PDB id:

6fsu

Name:

Membrane protein

Title:

Crystal structure of e.Coli bama beta-barrel with a c-terminal extension

Structure:

Outer membrane protein assembly factor bama. Chain: a, b. Engineered: yes

Source:

Escherichia coli o157:h7. Organism_taxid: 83334. Gene: bama, yaet, z0188, ecs0179. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

2.60Å R-factor: 0.271 R-free: 0.298

Authors:

M.Zahn,J.-B.Hartmann,S.Hiller

Key ref:

J.B.Hartmann et al. (2018). Sequence-Specific Solution NMR Assignments of the β-Barrel Insertase BamA to Monitor Its Conformational Ensemble at the Atomic Level. J Am Chem Soc, 140, 11252-11260. PubMed id: 30125090 DOI: 10.1021/jacs.8b03220

Date:

20-Feb-18 Release date: 14-Nov-18

Protein chains

P0A940  (BAMA_ECOLI) -  Outer membrane protein assembly factor BamA from Escherichia coli (strain K12)

Seq: 810 a.a.

Struc: 388 a.a.*

* PDB and UniProt seqs differ at 9 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1021/jacs.8b03220

J Am Chem Soc 140:11252-11260 (2018)

PubMed id: 30125090

Sequence-Specific Solution NMR Assignments of the β-Barrel Insertase BamA to Monitor Its Conformational Ensemble at the Atomic Level.

J.B.Hartmann, M.Zahn, I.M.Burmann, S.Bibow, S.Hiller.

ABSTRACT

β-barrel outer membrane proteins (Omps) are key functional components of the outer membranes of Gram-negative bacteria, mitochondria, and plastids. In bacteria, their biogenesis requires the β-barrel-assembly machinery (Bam) with the central insertase BamA, but the exact translocation and insertion mechanism remains elusive. The BamA insertase features a loosely closed gating region between the first and last β-strand 16. Here, we describe ∼70% complete sequence-specific NMR resonance assignments of the transmembrane region of the BamA β-barrel in detergent micelles. On the basis of the assignments, NMR spectra show that the BamA barrel populates a conformational ensemble in slow exchange equilibrium, both in detergent micelles and lipid bilayer nanodiscs. Individual conformers can be selected from the ensemble by the introduction of a C-terminal strand extension, single-point mutations, or specific disulfide cross-linkings, and these modifications at the barrel seam are found to be allosterically coupled to sites at the entire barrel circumference. The resonance assignment provides a platform for mechanistic studies of BamA at atomic resolution, as well as for investigating interactions with potential antibiotic drugs and partner proteins.