Conformational snapshots of the bacitracin sensing and resistance transporter BceAB

Proc Natl Acad Sci U S A. 2022 Apr 5;119(14):e2123268119. doi: 10.1073/pnas.2123268119. Epub 2022 Mar 29.


SignificanceMany gram-positive organisms have evolved an elegant solution to sense and resist antimicrobial peptides that inhibit cell-wall synthesis. These organisms express an unusual "Bce-type" adenosine triphosphate-binding cassette (ABC) transporter that recognizes complexes formed between antimicrobial peptides and lipids involved in cell-wall biosynthesis. In this work, we provide the first structural snapshots of a Bce-type ABC transporter trapped in different conformational states. Our structures and associated biochemical data provide key insights into the novel target protection mechanism that these unusual ABC transporters use to sense and resist antimicrobial peptides. The studies described herein set the stage to begin developing a comprehensive molecular understanding of the diverse interactions between antimicrobial peptides and conserved resistance machinery found across most gram-positive organisms.

Keywords: antimicrobial; bacitracin; cryo-EM.

MeSH terms

  • ATP-Binding Cassette Transporters / metabolism
  • Anti-Bacterial Agents / pharmacology
  • Bacillus subtilis / metabolism
  • Bacitracin* / metabolism
  • Bacitracin* / pharmacology
  • Bacterial Proteins / metabolism
  • Drug Resistance, Bacterial*
  • Gene Expression Regulation, Bacterial
  • Membrane Transport Proteins / metabolism


  • ATP-Binding Cassette Transporters
  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Membrane Transport Proteins
  • Bacitracin