Spectroscopic Investigation of the Kinetic Mechanism Involved in the Association of Potyviral VPg with the Host Plant Translation Initiation Factor eIF4E

International Journal of Molecular Sciences

Justine Charon¹  Thierry Michon²  Geneviève Tavert-Roudet²  Amandine Barra²  Jocelyne Walter² 

[1] Faculty of Sciences, University of Sydney, Charles Perkins Center D17, Camperdown Campus, Sydney, NSW 2006, Australia;INRAE, Biologie du Fruit et Pathologie, University of Bordeaux, UMR 1332, F-33140 Villenave d’Ornon, France;

关键词: intrinsically disordered protein;    eIF4E;    VPg;    potyvirus;    induced folding;    protein–protein interaction;   

DOI  :  10.3390/ijms21165618

来源: DOAJ

【 摘 要 】

The infectious cycle of potyviruses requires the formation of a complex between the viral genome-linked protein VPg and the host eukaryotic translation initiation factor 4E, eIF4E. Mutations associated with plant resistance to potyviruses were previously mapped at the eIF4E surface, while on the virus side, mutations leading to plant resistance breaking were identified within the VPg. In the present study, fluorescence spectroscopy was used to probe the contribution of the VPg intrinsically disordered region bearing amino acids determinant of the resistance breaking, to the VPg–eIF4E binding mechanism. Synthetic peptides encompassing the VPg_88–120 central region were found to tightly bind to eIF4E. Fluorescence energy transfer experiments show that, upon binding to eIF4E, the N and C termini of the VPg_88–111 fragment move closer to one another, at a distance compatible with a α-helix folding. When the VPg_112–120 region, which contains amino acids associated with resistance breakdown, is appended to VPg_88–111, the complex formation with eIF4E switches from a single-step to a two-step kinetic model. This study revisits a recent investigation of the VPg–eIF4E complex by specifying the contribution of the VPg central helix and its appended disordered region to VPg association with eIF4E.

【 授权许可】

Unknown