The structure of Erwinia amylovora AvrRpt2 provides insight into protein maturation and induced resistance to fire blight by Malus × robusta 5

DOI: 10.1016/j.jsb.2019.03.010

Authors: Joseph D. Bartho (Free University of Bolzano) , Nicola Demitri (Elettra – Sincrotrone Trieste) , Dom Bellini (Diamond Light Source; Research Complex at Harwell) , Henryk Flachowsky (Julius Kühn-Institut) , Andreas Peil (Julius Kühn-Institut) , Martin Walsh (Diamond Light Source) , Stefano Benini (Free University of Bolzano)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Structural Biology

State: Published (Approved)
Published: March 2019

Abstract: The AvrRpt2 protein of the phytopathogenic bacterium Erwinia amylovora (AvrRpt2EA) is a secreted type III effector protein, which is recognised by the FB_MR5 resistance protein of Malus × robusta 5, the only identified resistance protein from a Malus species preventing E. amylovora infection. The crystal structure of the immature catalytic domain of AvrRpt2EA, a C70 family cysteine protease and type III effector, was determined to a resolution of 1.85 Å. The structure provides insights into the cyclophilin-dependent activation of AvrRpt2, and identifies a cryptic leucine of a non-canonical cyclophilin binding motif. The structure also suggests that residue Cys156, responsible for the gene induced resistance, is not involved in substrate determination, and hints that recognition by FB_MR5 is due to direct interaction.

Journal Keywords: Cysteine protease; Effector; T3SS; Cyclophilin; Plant resistance

Subject Areas: Biology and Bio-materials

Facility: Elettra Sincrotrone