Expression, purification and structural characterization of capsidial proteins coded by grapevine virus a and grapevine virus b

• Grant number: 10/00896-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2010
• End date: May 31, 2014
• Field of knowledge: Biological Sciences - Biophysics - Molecular Biophysics
• Principal Investigator: Raghuvir Krishnaswamy Arni
• Grantee: Vinícius dos Santos Santana
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil
• Associated scholarship(s): 11/23524-0 - Expression, purification and structural characterization of capsidial proteins coded by grapevine virus a and grapevine virus b, BE.EP.DR

Abstract

Grapevine virus A and Grapevine virus B are members of the genus Vitivirus, in the family Flexiviridae. They are causative agents responsible for diseases in grapevines and are considered to be of great economic importance for viticulture. Virions are flexuous filaments, contain a single positive stranded RNA, are strictly phloem-limited, and are restricted to a single host, the grapevine. Several GVA and GVB molecular characterization studies have been reported, for instance, genomic RNA sequencing, subgenomic RNA detection and strategy for expression of the virus genome. The coat protein gene has been characterized, however, there are few structural studies related to these proteins. The failure to obtain some of these viral proteins from infected plant extracts is due its low concentration, thus, becoming difficult to study the function of these proteins during viral replication, as well as in structural studies. Therefore, the aim of this project is to express GVA and GVB capsid proteins on a large scale as well as high-purity purification and to use protein refolding assays for crystallization. The crystallization assays may lead to the resolution of the protein crystallographic structures, which will provide relevant information to understand their functions during viral replication and movement of the particles in host plants.