title: Modular structure of HEL protein from Arabidopsis reveals new potential functions for PR-4 proteins.
abstract: Plants possess an innate immune system enabling them to defend themselves against pathogen attack.The accumulation of newly synthesized pathogenesis related proteins (PRs) is one of the most studied inducible plant defence response. In this paper, we report on the characterization of a class I PR4 vacuolar protein from Arabidopsis, named At HEL. The protein has a modular structure consisting of an N-terminal hevein-like domain(CB-HEL) and a C-terminal domain (CD-HEL) that are posttranslationally processed. Both domains show a strong antifungal activity, but they do not have chitinolitic properties.CD-HEL was found to be endowed with RNase, but not DNase activity. Molecular modeling carried out on both domains revealed that CB-HEL possesses a chitin binding site strictly conserved between hevein-type peptides and that the cavity involved in substrate interaction of CD-HEL do not show any residue substitution with respect to the orthologous wheatwin1 from wheat. Using a fishing for partners approach, CB-HEL was found to interact with a fungal fruiting body lectin. According to literature, we can hypothesize that CB-HEL could cross the pathogen hyphal membrane and that its interaction with a fungal lectin could knock out one of the weapons that the fungus uses.
authors: Department of Ecological and Biological Sciences, University of Tuscia, Via S. Camillo de Lellis, I-01100 Viterbo, Italy.
authors: Laura
authors: L
authors: Bertini
authors: Silvia
authors: S
authors: Proietti
authors: Maria Pia
authors: MP
authors: Aleandri
authors: Francesca
authors: F
authors: Mondello
authors: Silvia
authors: S
authors: Sandini
authors: Carlo
authors: C
authors: Caporale
authors: Carla
authors: C
authors: Caruso
mesh_terms: D000935:Antifungal Agents / Q000032:analysis / Q000378:metabolism; D023181:Antimicrobial Cationic Peptides / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism*; D002688:Chitinases / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D037121:Plant Lectins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D012260:Ribonucleases / Q000032:analysis / Q000235:genetics / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D029681:Arabidopsis Proteins; C582103:HEL protein, Arabidopsis; D008565:Membrane Proteins; D037121:Plant Lectins; D011994:Recombinant Proteins; C045875:hevein; D012260:Ribonucleases; D002688:Chitinases