1UKF

Crystal Structure of Pseudomonas Avirulence Protein AvrPphB

Summary for 1UKF

• Entry DOI: 10.2210/pdb1ukf/pdb
• Descriptor: Avirulence protein AVRPPH3 (2 entities in total)
• Functional Keywords: avrpphb, avrpph3, avirulence, hypersensitive response, hydrolase
• Biological source: Pseudomonas syringae pv. phaseolicola
• Cellular location: Secreted: Q52430
• Total number of polymer chains: 1
• Total formula weight: 20387.29

Authors

Zhu, M.,Shao, F.,Innes, R.W.,Dixon, J.E.,Xu, Z. (deposition date: 2003-08-21, release date: 2003-12-09, Last modification date: 2023-12-27)

Primary citation

Zhu, M.,Shao, F.,Innes, R.W.,Dixon, J.E.,Xu, Z.
The crystal structure of Pseudomonas avirulence protein AvrPphB: a papain-like fold with a distinct substrate-binding site.
Proc.Natl.Acad.Sci.Usa, 101:302-307, 2004

PubMed Abstract: AvrPphB is an avirulence (Avr) protein from the plant pathogen Pseudomonas syringae that can trigger a disease-resistance response in a number of host plants including Arabidopsis. AvrPphB belongs to a novel family of cysteine proteases with the charter member of this family being the Yersinia effector protein YopT. AvrPphB has a very stringent substrate specificity, catalyzing a single proteolytic cleavage in the Arabidopsis serine/threonine kinase PBS1. We have determined the crystal structure of AvrPphB by x-ray crystallography at 1.35-A resolution. The structure is composed of a central antiparallel beta-sheet, with alpha-helices packing on both sides of the sheet to form a two-lobe structure. The core of this structure resembles the papain-like cysteine proteases. The similarity includes the AvrPphB active site catalytic triad of Cys-98, His-212, and Asp-227 and the oxyanion hole residue Asn-93. Based on analogy with inhibitor complexes of the papain-like proteases, we propose a model for the substrate-binding mechanism of AvrPphB. A deep and positively charged pocket (S2) and a neighboring shallow surface (S3) likely bind to aspartic acid and glycine residues in the substrate located two (P2) and three (P3) residues N terminal to the cleavage site, respectively. Further implications about the specificity of plant pathogen recognition are also discussed.

PubMed: 14694194
DOI: 10.1073/pnas.2036536100

Experimental method

X-RAY DIFFRACTION (1.35 Å)