Molecular basis of V-ATPase inhibition by bafilomycin A1

Nat Commun. 2021 Mar 19;12(1):1782. doi: 10.1038/s41467-021-22111-5.

Abstract

Pharmacological inhibition of vacuolar-type H+-ATPase (V-ATPase) by its specific inhibitor can abrogate tumor metastasis, prevent autophagy, and reduce cellular signaling responses. Bafilomycin A1, a member of macrolide antibiotics and an autophagy inhibitor, serves as a specific and potent V-ATPases inhibitor. Although there are many V-ATPase structures reported, the molecular basis of specific inhibitors on V-ATPase remains unknown. Here, we report the cryo-EM structure of bafilomycin A1 bound intact bovine V-ATPase at an overall resolution of 3.6-Å. The structure reveals six bafilomycin A1 molecules bound to the c-ring. One bafilomycin A1 molecule engages with two c subunits and disrupts the interactions between the c-ring and subunit a, thereby preventing proton translocation. Structural and sequence analyses demonstrate that the bafilomycin A1-binding residues are conserved in yeast and mammalian species and the 7'-hydroxyl group of bafilomycin A1 acts as a unique feature recognized by subunit c.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Biocatalysis / drug effects
  • Cattle
  • Cryoelectron Microscopy
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / metabolism
  • Enzyme Inhibitors / pharmacology
  • Macrolides / chemistry
  • Macrolides / metabolism
  • Macrolides / pharmacology*
  • Models, Molecular
  • Molecular Structure
  • Protein Binding
  • Protein Domains
  • Sequence Homology, Amino Acid
  • Vacuolar Proton-Translocating ATPases / antagonists & inhibitors*
  • Vacuolar Proton-Translocating ATPases / chemistry
  • Vacuolar Proton-Translocating ATPases / ultrastructure

Substances

  • Enzyme Inhibitors
  • Macrolides
  • bafilomycin A1
  • Vacuolar Proton-Translocating ATPases