The crystal structure of polygalacturonase-inhibiting protein (PGIP), a leucine-rich repeat protein involved in plant defense.
Polygalacturonase-inhibiting proteins (PGIPs) are plant cell wall proteins that protect plants from fungal invasion. They interact with endopolygalacturonases secreted by phytopathogenic fungi, inhibit their enzymatic activity, and favor the accumulation of oligogalacturonides, which activate plant defense responses. PGIPs are members of the leucine-rich repeat (LRR) protein family that in plants play crucial roles in development, defense against pathogens, and recognition of beneficial microbes. Here we report the crystal structure at 1.7-A resolution of a PGIP from Phaseolus vulgaris. The structure is characterized by the presence of two beta-sheets instead of the single one originally predicted by modeling studies. The structure also reveals a negatively charged surface on the LRR concave face, likely involved in binding polygalacturonases. The structural information on PGIP provides a basis for designing more efficient inhibitors for plant protection.
Di Matteo
A
A
Department of Biochemical Sciences and Consiglio Nazionale delle Ricerche, Institute for Molecular Biology and Pathology, University of Rome La Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy.
Federici
L
L
Mattei
B
B
Salvi
G
G
Johnson
K A
KA
Savino
C
C
De Lorenzo
G
G
Tsernoglou
D
D
Cervone
F
F
D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000737:chemistry; D005658:Fungi / Q000201:enzymology / Q000472:pathogenicity; D017343:Genes, Plant; D008958:Models, Molecular; D008969:Molecular Sequence Data; D027805:Phaseolus / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D011096:Polygalacturonase / Q000037:antagonists & inhibitors; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D055672:Static Electricity
D004791:Enzyme Inhibitors; C081479:PGIP protein, plant; D010940:Plant Proteins; D020033:Protein Isoforms; D011994:Recombinant Proteins; D011096:Polygalacturonase