6BL6

Crystallization of lipid A transporter MsbA from Salmonella typhimurium


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.270 
  • R-Value Observed: 0.271 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Structural Insights into the Lipid A Transport Pathway in MsbA.

Padayatti, P.S.Lee, S.C.Stanfield, R.L.Wen, P.C.Tajkhorshid, E.Wilson, I.A.Zhang, Q.

(2019) Structure 27: 1114

  • DOI: 10.1016/j.str.2019.04.007
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • MsbA is an essential ATP-binding cassette transporter in Gram-negative bacteria that transports lipid A and lipopolysaccharide from the cytoplasmic leaflet to the periplasmic leaflet of the inner membrane. Here we report the X-ray structure of MsbA f ...

    MsbA is an essential ATP-binding cassette transporter in Gram-negative bacteria that transports lipid A and lipopolysaccharide from the cytoplasmic leaflet to the periplasmic leaflet of the inner membrane. Here we report the X-ray structure of MsbA from Salmonella typhimurium at 2.8-Å resolution in an inward-facing conformation after cocrystallization with lipid A and using a stabilizing facial amphiphile. The structure displays a large amplitude opening in the transmembrane portal, which is likely required for lipid A to pass from its site of synthesis into the protein-enclosed transport pathway. Putative lipid A density is observed further inside the transmembrane cavity, consistent with a trap and flip model. Additional electron density attributed to lipid A is observed near an outer surface cleft at the periplasmic ends of the transmembrane helices. These findings provide new structural insights into the lipid A transport pathway through comparative analysis with existing MsbA structures.


    Organizational Affiliation

    Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA. Electronic address: qinghai@scripps.edu.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Lipid A export ATP-binding/permease protein MsbA
A, B
576Salmonella enterica subsp. enterica serovar Typhimurium str. LT2Mutation(s): 1 
Gene Names: msbASTM0984
EC: 3.6.3 (PDB Primary Data), 7.5.2.6 (UniProt)
Membrane protein
Mpstruc
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
ATP Binding Cassette (ABC) Transporters
Protein: 
MsbA Lipid "flippase" with bound lipid A
Find proteins for P63359 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  P63359
Protein Feature View
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.270 
  • R-Value Observed: 0.271 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 82.052α = 90
b = 154.819β = 90
c = 228.886γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR01 GM118594
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR01 GM098538

Revision History 

  • Version 1.0: 2019-01-09
    Type: Initial release
  • Version 1.1: 2019-01-16
    Changes: Author supporting evidence, Data collection, Structure summary
  • Version 1.2: 2019-06-12
    Changes: Data collection, Database references, Structure summary
  • Version 1.3: 2019-07-17
    Changes: Data collection, Database references
  • Version 1.4: 2020-01-01
    Changes: Author supporting evidence