<i>Pseudomonas</i> effector AvrB is a glycosyltransferase that rhamnosylates plant guardee protein RIN4.

ABSTRACT: The plant pathogen Pseudomonas syringae encodes a type III secretion system avirulence effector protein, AvrB, that induces a form of programmed cell death called the hypersensitive response in plants as a defense mechanism against systemic infection. Despite the well-documented catalytic activities observed in other Fido (Fic, Doc, and AvrB) proteins, the enzymatic activity and target substrates of AvrB have remained elusive. Here, we show that AvrB is an unprecedented glycosyltransferase that transfers rhamnose from UDP-rhamnose to a threonine residue of the Arabidopsis guardee protein RIN4. We report structures of various enzymatic states of the AvrB-catalyzed rhamnosylation reaction of RIN4, which reveal the structural and mechanistic basis for rhamnosylatio

SUBMITTER: Peng W 

PROVIDER: S-EPMC10866546 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature