PDBsum entry 4z4a

Sugar binding protein

PDB id: 4z4a

Contents

Protein chains

74 a.a.

Ligands

EDO ×16

Waters ×149

PDB id:

4z4a

Name:

Sugar binding protein

Title:

Avirulence protein 4 (avr4) from pseudocercospora fuligena

Structure:

Carbohydrate-binding module family 14 protein. Chain: a, b. Engineered: yes

Source:

Pseudocercospora fuligena. Organism_taxid: 685502. Expressed in: komagataella pastoris gs115. Expression_system_taxid: 644223.

Resolution:

1.70Å R-factor: 0.184 R-free: 0.210

Authors:

N.K.Hurlburt,A.C.Kohler,A.J.Fisher

Key ref:

A.C.Kohler et al. (2016). Structural Analysis of an Avr4 Effector Ortholog Offers Insight into Chitin Binding and Recognition by the Cf-4 Receptor. Plant Cell, 28, 1945-1965. PubMed id: 27401545 DOI: 10.1105/tpc.15.00893

Date:

01-Apr-15 Release date: 29-Jun-16

Protein chains

M3AZE0  (M3AZE0_PSEFD) -  Carbohydrate-binding module family 14 protein from Pseudocercospora fijiensis (strain CIRAD86)

Seq: 121 a.a.

Struc: 74 a.a.*

* PDB and UniProt seqs differ at 10 residue positions (black crosses)

DOI no: 10.1105/tpc.15.00893

Plant Cell 28:1945-1965 (2016)

PubMed id: 27401545

Structural Analysis of an Avr4 Effector Ortholog Offers Insight into Chitin Binding and Recognition by the Cf-4 Receptor.

A.C.Kohler, L.H.Chen, N.Hurlburt, A.Salvucci, B.Schwessinger, A.J.Fisher, I.Stergiopoulos.

ABSTRACT

Chitin is a key component of fungal cell walls and a potent inducer of innate immune responses. Consequently, fungi may secrete chitin-binding lectins, such as the Cf-Avr4 effector protein from the tomato pathogen Cladosporium fulvum, to shield chitin from host-derived chitinases during infection. Homologs of Cf-Avr4 are found throughout Dothideomycetes, and despite their modest primary sequence identity, many are perceived by the cognate tomato immune receptor Cf-4. Here, we determined the x-ray crystal structure of Pf-Avr4 from the tomato pathogen Pseudocercospora fuligena, thus providing a three-dimensional model of an Avr4 effector protein. In addition, we explored structural, biochemical, and functional aspects of Pf-Avr4 and Cf-Avr4 to further define the biology of core effector proteins and outline a conceptual framework for their pleiotropic recognition by single immune receptors. We show that Cf-Avr4 and Pf-Avr4 share functional specificity in binding (GlcNAc)6 and in providing protection against plant- and microbial-derived chitinases, suggesting a broader role beyond deregulation of host immunity. Furthermore, structure-guided site-directed mutagenesis indicated that residues in Pf-Avr4 important for binding chitin do not directly influence recognition by Cf-4 and further suggested that the property of recognition is structurally separated or does not fully overlap with the virulence function of the effector.