Structural basis of nanobody-recognition of grapevine fanleaf virus and of virus resistance loss

Autor: Bernard Lorber, Sophie Gersch, Emmanuelle Vigne, Corinne Schmitt-Keichinger, Serge Muyldermans, Kamal Hleibieh, Vianney Poignavent, Lorène Belval, Patrick Bron, Pascale Schellenberger, Jean-Michel Hily, Gérard Demangeat, Bruno P. Klaholz, Ahmed Ghannam, Léa Ackerer, Igor Orlov, Véronique Komar, Olivier Lemaire, Caroline Hemmer, Christophe Ritzenthaler, Aurélie Marmonier, Claude Sauter
Přispěvatelé: Institut de génétique et biologie moléculaire et cellulaire (IGBMC), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Louis Pasteur - Strasbourg I, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut de biologie moléculaire des plantes (IBMP), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Architecture et réactivité de l'ARN (ARN), Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Architecture et Réactivité de l'ARN (ARN), Institut de biologie moléculaire et cellulaire (IBMC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), ANR-14-CE19-0022,COMBiNiNG,Résistances antivirales combinées pour lutter contre la maladie du court-noué de la vigne(2014), ANR-10-INBS-0005,FRISBI,Infrastructure Française pour la Biologie Structurale Intégrée(2010), Université Louis Pasteur - Strasbourg I-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)
Jazyk: angličtina
Rok vydání: 2019
Předmět:
DOI: 10.1101/728907
Popis: Grapevine fanleaf virus (GFLV) is a picorna-like plant virus transmitted by nematodes that affects vineyards worldwide. Nanobody (Nb)-mediated resistance against GFLV has been created recently and shown to be highly effective in plants including grapevine, but the underlying mechanism is unknown. Here we present the high-resolution cryo-EM structure of the GFLV-Nb23 complex which provides the basis for the molecular recognition by the nanobody. The structure reveals a composite binding site bridging over 3 domains of the capsid protein (CP) monomer. The structure provides a precise mapping of the Nb23 epitope on the GFLV capsid in which the antigen loop is accommodated through an induced fit mechanism. Moreover, we uncover and characterize several resistance-breaking GFLV isolates with amino acids mapping within this epitope, including C-terminal extensions of the CP, which would sterically interfere with Nb binding. Escape variants with such extended CP fail to be transmitted by nematodes linking Nb-mediated resistance to vector transmission. Together, these data provide insights into the molecular mechanism of Nb23-mediated recognition of GFLV and of virus resistance loss.SignificanceGrapevine fanleaf virus (GFLV) is a picorna-like plant virus that severely impacts vineyards worldwide. While Nanobodies (Nb) confer resistance to GFLV in plants the underlying molecular mechanism of action is unknown. Here we present the high-resolution cryo-EM structure of the GFLV-Nb complex. It uncovers the conformational epitope on the capsid surface which is a composite binding site into which the antigen loop is accommodated through an induced fit mechanism. Furthermore, we describe several resistance-breaking isolates of GFLV with reduced Nb binding capacity. Those that carry a C-terminal extension also fail to be transmitted by nematodes. Together, these data provide structure-function insights into the Nb-GFLV recognition and the molecular mechanism leading to loss of resistance.
Databáze: OpenAIRE
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