The structural basis of Salmonella A2B5 toxin neutralization by antibodies targeting the glycan-receptor binding subunits. Academic Article uri icon

Overview

abstract

  • Many bacterial pathogens secrete A(2)B5 toxins comprising two functionally distinct yet complementary "A" and "B" subunits to benefit the pathogens during infection. The lectin-like pentameric B subunits recognize specific sets of host glycans to deliver the toxin into target host cells. Here, we offer the molecular mechanism by which neutralizing antibodies, which have the potential to bind to all glycan-receptor binding sites and thus completely inhibit toxin binding to host cells, are inhibited from exerting this action. Cryogenic electron microscopy (cryo-EM)-based analyses indicate that the skewed positioning of the toxin A subunit(s) toward one side of the toxin B pentamer inhibited neutralizing antibody binding to the laterally located epitopes, rendering some glycan-receptor binding sites that remained available for the toxin binding and endocytosis process, which is strikingly different from the counterpart antibodies recognizing the far side-located epitopes. These results highlight additional features of the toxin-antibody interactions and offer important insights into anti-toxin strategies.

publication date

  • September 7, 2021

Research

keywords

  • Bacterial Toxins
  • Polysaccharides
  • Protein Binding
  • Salmonella

Identity

PubMed Central ID

  • PMC8459933

Scopus Document Identifier

  • 85114238867

Digital Object Identifier (DOI)

  • 10.1016/j.tim.2021.06.011

PubMed ID

  • 34496256

Additional Document Info

volume

  • 36

issue

  • 10