5LJ9

Structure of the E. coli MacB ABC domain (C2221)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.188 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structure and mechanotransmission mechanism of the MacB ABC transporter superfamily.

Crow, A.Greene, N.P.Kaplan, E.Koronakis, V.

(2017) Proc Natl Acad Sci U S A 114: 12572-12577

  • DOI: 10.1073/pnas.1712153114
  • Primary Citation of Related Structures:  
    5NAA, 5LIL, 5LJA, 5LJ6, 5LJ8, 5LJ7, 5LJ9

  • PubMed Abstract: 
  • MacB is an ABC transporter that collaborates with the MacA adaptor protein and TolC exit duct to drive efflux of antibiotics and enterotoxin STII out of the bacterial cell. Here we present the structure of ATP-bound MacB and reveal precise molecular details of its mechanism ...

    MacB is an ABC transporter that collaborates with the MacA adaptor protein and TolC exit duct to drive efflux of antibiotics and enterotoxin STII out of the bacterial cell. Here we present the structure of ATP-bound MacB and reveal precise molecular details of its mechanism. The MacB transmembrane domain lacks a central cavity through which substrates could be passed, but instead conveys conformational changes from one side of the membrane to the other, a process we term mechanotransmission. Comparison of ATP-bound and nucleotide-free states reveals how reversible dimerization of the nucleotide binding domains drives opening and closing of the MacB periplasmic domains via concerted movements of the second transmembrane segment and major coupling helix. We propose that the assembled tripartite pump acts as a molecular bellows to propel substrates through the TolC exit duct, driven by MacB mechanotransmission. Homologs of MacB that do not form tripartite pumps, but share structural features underpinning mechanotransmission, include the LolCDE lipoprotein trafficking complex and FtsEX cell division signaling protein. The MacB architecture serves as the blueprint for understanding the structure and mechanism of an entire ABC transporter superfamily and the many diverse functions it supports.


    Organizational Affiliation

    Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom vk103@cam.ac.uk.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Macrolide export ATP-binding/permease protein MacBA, B, C231Escherichia coli K-12Mutation(s): 0 
Gene Names: macBybjZb0879JW0863
EC: 3.6.3 (PDB Primary Data), 7.6.2 (UniProt)
Membrane protein
Mpstruc
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
ATP Binding Cassette (ABC) Transporters
Protein: 
MacB ABC tranporter with bound ATPγS (P21)
Find proteins for P75831 (Escherichia coli (strain K12))
Explore P75831 
Go to UniProtKB:  P75831
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.188 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 57.47α = 90
b = 96.21β = 90
c = 262.71γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
iMOSFLMdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data

  • Deposited Date: 2016-07-18 
  • Released Date: 2017-11-15 
  • Deposition Author(s): Crow, A.

Funding OrganizationLocationGrant Number
Medical Research Council (United Kingdom)United KingdomMR/N000994/1

Revision History  (Full details and data files)

  • Version 1.0: 2017-11-15
    Type: Initial release
  • Version 1.1: 2017-11-29
    Changes: Database references
  • Version 1.2: 2018-01-24
    Changes: Source and taxonomy