PDBsum entry: 1hg8

Hydrolase

PDB id: 1hg8

Contents

Protein chain

349 a.a. *

Ligands

NAG

NAG-NAG

Waters ×326

* Residue conservation analysis

PDB id:

1hg8

Name:

Hydrolase

Title:

Endopolygalacturonase from the phytopathogenic fungus fusarium moniliforme

Structure:

Endopolygalacturonase. Chain: a. Engineered: yes

Source:

Fusarium moniliforme. Organism_taxid: 117187. Expressed in: saccharomyces cerevisiae. Expression_system_taxid: 4932

Resolution:

1.73Å R-factor: 0.172 R-free: 0.203

Authors:

L.Federici,C.Caprari,B.Mattei,C.Savino,G.De Lorenzo, F.Cervone,D.Tsernoglou

Key ref:

L.Federici et al. (2001). Structural requirements of endopolygalacturonase for the interaction with PGIP (polygalacturonase-inhibiting protein). Proc Natl Acad Sci U S A, 98, 13425-13430. PubMed id: 11687632 DOI: 10.1073/pnas.231473698

Date:

13-Dec-00 Release date: 10-Nov-01

Protein chain

Q07181  (PGLR_GIBFU) -  Polygalacturonase

Seq: 373 a.a.

Struc: 349 a.a.

Enzyme reactions

• Enzyme class: E.C.3.2.1.15 - Polygalacturonase.
• Reaction: Random hydrolysis of 1,4-alpha-D-galactosiduronic linkages in pectate and other galacturonans.

 Gene Ontology (GO) functional annotation 

• Cellular component: extracellular region (1 term)
• Biological process: metabolic process (3 terms)
• Biochemical function: hydrolase activity (3 terms)

DOI no: 10.1073/pnas.231473698

Proc Natl Acad Sci U S A 98:13425-13430 (2001)

PubMed id: 11687632

Structural requirements of endopolygalacturonase for the interaction with PGIP (polygalacturonase-inhibiting protein).

L.Federici, C.Caprari, B.Mattei, C.Savino, A.Di Matteo, G.De Lorenzo, F.Cervone, D.Tsernoglou.

ABSTRACT

To invade a plant tissue, phytopathogenic fungi produce several cell wall-degrading enzymes; among them, endopolygalacturonase (PG) catalyzes the fragmentation and solubilization of homogalacturonan. Polygalacturonase-inhibiting proteins (PGIPs), found in the cell wall of many plants, counteract fungal PGs by forming specific complexes with them. We report the crystal structure at 1.73 A resolution of PG from the phytopathogenic fungus Fusarium moniliforme (FmPG). The structure of FmPG was useful to study the mode of interaction of the enzyme with PGIP-2 from Phaseolus vulgaris. Several amino acids of FmPG were mutated, and their contribution to the formation of the complex with PGIP-2 was investigated by surface plasmon resonance. The residues Lys-269 and Arg-267, located inside the active site cleft, and His-188, at the edge of the active site cleft, are critical for the formation of the complex, which is consistent with the observed competitive inhibition of the enzyme played by PGIP-2. The replacement of His-188 with a proline or the insertion of a tryptophan after position 270, variations that both occur in plant PGs, interferes with the formation of the complex. We suggest that these variations are important structural requirements of plant PGs to prevent PGIP binding.

Selected figure(s)

Figure 2.
Fig. 2. Structural superposition between FmPG (in red) and AnPGII (in blue) represented as protein ribbons. The superposition was performed by matching identical residues with the automated procedure implemented in the program INSIGHTII.

Figure 5.
Fig. 5. FmPG structure with the tryptophan residue inserted after position 270 (S270insW). The structure of the wild-type enzyme is shown in red and the model structure of the mutated enzyme in blue.

Figures were selected by an automated process.