PDBsum entry 6v0c

Lipid transport

PDB id: 6v0c

Contents

Protein chains

(+ 0 more) 832 a.a.

PDB id:

6v0c

Name:

Lipid transport

Title:

Lipophilic envelope-spanning tunnel b (letb), model 1

Structure:

Intermembrane transport protein yebt. Chain: a, b, c, d, e, f. Engineered: yes

Source:

Escherichia coli (strain k12). Organism_taxid: 83333. Strain: k12. Gene: yebt, b1834, jw1823. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008

Authors:

G.L.Isom,N.Coudray,M.R.Macrae,C.T.Mcmanus,D.C.Ekiert,G.Bhabha

Key ref:

G.L.Isom et al. (2020). LetB Structure Reveals a Tunnel for Lipid Transport across the Bacterial Envelope. Cell, 181, 653. PubMed id: 32359438 DOI: 10.1016/j.cell.2020.03.030

Date:

18-Nov-19 Release date: 06-May-20

Protein chains

P76272  (YEBT_ECOLI) -  Intermembrane transport protein YebT from Escherichia coli (strain K12)

Seq: 877 a.a.

Struc: 832 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1016/j.cell.2020.03.030

Cell 181:653 (2020)

PubMed id: 32359438

LetB Structure Reveals a Tunnel for Lipid Transport across the Bacterial Envelope.

G.L.Isom, N.Coudray, M.R.MacRae, C.T.McManus, D.C.Ekiert, G.Bhabha.

ABSTRACT

Gram-negative bacteria are surrounded by an outer membrane composed of phospholipids and lipopolysaccharide, which acts as a barrier and contributes to antibiotic resistance. The systems that mediate phospholipid trafficking across the periplasm, such as MCE (Mammalian Cell Entry) transporters, have not been well characterized. Our ~3.5 Å cryo-EM structure of the E. coli MCE protein LetB reveals an ~0.6 megadalton complex that consists of seven stacked rings, with a central hydrophobic tunnel sufficiently long to span the periplasm. Lipids bind inside the tunnel, suggesting that it functions as a pathway for lipid transport. Cryo-EM structures in the open and closed states reveal a dynamic tunnel lining, with implications for gating or substrate translocation. Our results support a model in which LetB establishes a physical link between the two membranes and creates a hydrophobic pathway for the translocation of lipids across the periplasm.