Pseudomonas effector AvrC is a rhamnosyltransferase with broad substrate specificity

Authors

Payne, N., Servage, K. A., Orth, K., Fernandez, J., Peng, W.

Abstract

Plant cells can directly or indirectly detect bacterial effectors, triggering a hypersensitive response to defend against pathogen infection. One extensively studied effector, AvrB, is a Fido (Fic, Doc, AvrB) domain-containing protein that acts as a glycosyltransferase. AvrC is an elusive Pseudomonas syringae avirulence effector protein with significant sequence and structural similarity to AvrB. Combining biochemistry, mass spectrometry, and AlphaFold prediction tools, we show that AvrC is a glycosyltransferase with auto-rhamnosylation activity. Like AvrB, AvrC can rhamnosylate a threonine residue (T166) on the A. thaliana guardee protein RIN4. In vitro assays revealed rhamnosylation substrates for AvrC also include plant coatomer subunits COPE1 and COPZ1. Collectively, our findings indicate that AvrC is a rhamnosyltransferase with broad substrate specificity. Our experimental strategies and findings provide valuable insights into future studies on the characterization of other Fido proteins.

Preprint server: bioRxiv
The authors list and abstract were imported from bioRxiv on 28 Aug 2026.

Stats

1-terrible, 9-excellent. How would you rate this preprint? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.