Structure of an antibacterial peptide ATP-binding cassette transporter in a novel outward occluded state

Choudhury, Hassanul G., Tong, Zhen, Mathavan, Indran, Li, Yanyan, Iwata, So, Zirah, Séverine, Rebuffat, Sylvie, Van Veen, Hendrik W. and Beis, Konstantinos (2014) Structure of an antibacterial peptide ATP-binding cassette transporter in a novel outward occluded state. Proceedings of the National Academy of Sciences of the United States of America, 111 25: 9145-9150. doi:10.1073/pnas.1320506111


Author Choudhury, Hassanul G.
Tong, Zhen
Mathavan, Indran
Li, Yanyan
Iwata, So
Zirah, Séverine
Rebuffat, Sylvie
Van Veen, Hendrik W.
Beis, Konstantinos
Title Structure of an antibacterial peptide ATP-binding cassette transporter in a novel outward occluded state
Journal name Proceedings of the National Academy of Sciences of the United States of America   Check publisher's open access policy
ISSN 1091-6490
0027-8424
Publication date 2014-06
Sub-type Article (original research)
DOI 10.1073/pnas.1320506111
Open Access Status DOI
Volume 111
Issue 25
Start page 9145
End page 9150
Total pages 6
Place of publication Washington DC United States
Publisher National Academy of Sciences
Collection year 2015
Language eng
Formatted abstract
Enterobacteriaceae produce antimicrobial peptides for survival under nutrient starvation. Microcin J25 (MccJ25) is an antimicrobial peptide with a unique lasso topology. It is secreted by the ATP-binding cassette (ABC) exporter McjD, which ensures self-immunity of the producing strain through efficient export of the toxic mature peptide from the cell. Here we have determined the crystal structure of McjD from Escherichia coli at 2.7-Å resolution, which is to the authors’ knowledge the first structure of an antibacterial peptide ABC transporter. Our functional and biochemical analyses demonstrate McjD-dependent immunity to MccJ25 through efflux of the peptide. McjD can directly bind MccJ25 and displays a basal ATPase activity that is stimulated by MccJ25 in both detergent solution and proteoliposomes. McjD adopts a new conformation, termed nucleotide-bound outward occluded. The new conformation defines a clear cavity; mutagenesis and ligand binding studies of the cavity have identified Phe86, Asn134, and Asn302 as important for recognition of MccJ25. Comparisons with the inward-open MsbA and outward-open Sav1866 structures show that McjD has structural similarities with both states without the intertwining of transmembrane (TM) helices. The occluded state is formed by rotation of TMs 1 and 2 toward the equivalent TMs of the opposite monomer, unlike Sav1866 where they intertwine with TMs 3–6 of the opposite monomer. Cysteine cross-linking studies on the McjD dimer in inside-out membrane vesicles of E. coli confirmed the presence of the occluded state. We therefore propose that the outward-occluded state represents a transition intermediate between the outward-open and inward-open conformation of ABC exporters.
Keyword Antimicrobial peptide ABC exporter
Membrane transporter crystal structure
Microcin immunity protein
Substrate binding
Transport mechanism
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Non HERDC
Institute for Molecular Bioscience - Publications
 
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