National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)
AI155453
米国
引用
ジャーナル: Cell Rep / 年: 2022 タイトル: Structural basis for non-canonical integrin engagement by Bordetella adenylate cyclase toxin. 著者: Jory A Goldsmith / Andrea M DiVenere / Jennifer A Maynard / Jason S McLellan / 要旨: Integrins are ubiquitous cell-surface heterodimers that are exploited by pathogens and toxins, including leukotoxins that target β integrins on phagocytes. The Bordetella adenylate cyclase toxin ...Integrins are ubiquitous cell-surface heterodimers that are exploited by pathogens and toxins, including leukotoxins that target β integrins on phagocytes. The Bordetella adenylate cyclase toxin (ACT) uses the αβ integrin as a receptor, but the structural basis for integrin binding and neutralization by antibodies is poorly understood. Here, we use cryoelectron microscopy to determine a 2.7 Å resolution structure of an ACT fragment bound to αβ. This structure reveals that ACT interacts with the headpiece and calf-2 of the α subunit in a non-canonical manner specific to bent, inactive αβ. Neutralizing antibody epitopes map to ACT residues involved in α binding, providing the basis for antibody-mediated attachment inhibition. Furthermore, binding to αβ positions the essential ACT acylation sites, which are conserved among toxins exported by type I secretion systems, at the cell membrane. These findings reveal a structural mechanism for integrin-mediated attachment and explain antibody-mediated neutralization of ACT intoxication.