5LJ9

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.186 

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:  

  • 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 ...

    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.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Macrolide export ATP-binding/permease protein MacB
A, B, C
231Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: macB (ybjZ)
EC: 3.6.3.-
Membrane protein
mpstruct
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))
Go to UniProtKB:  P75831
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.186 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 57.470α = 90.00
b = 96.210β = 90.00
c = 262.710γ = 90.00
Software Package:
Software NamePurpose
iMOSFLMdata reduction
PHASERphasing
Aimlessdata scaling
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



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 

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