Structural studies of the enzymes involved in the biosynthesis of the exopolysaccharide, xylellan gum, produced by xylella fastidiosa.

• Processo: 01/07545-5
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Data de Início da vigência: 01 de outubro de 2001
• Data de Término da vigência: 30 de abril de 2006
• Área do conhecimento: Ciências Biológicas - Bioquímica
• Pesquisador responsável: Dulce Helena Ferreira de Souza
• Beneficiário: Dulce Helena Ferreira de Souza
• Instituição Sede: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brasil
• Assunto(s): Xylella fastidiosa
• Palavra(s)-Chave do Pesquisador: Exopolisacarideo | Peron Gum | Structure | Xylella Fastidiosa | Xylellan Gum

Resumo

Citrus variegated chlorosis (CVC) is the disease "amarelinho" that affects orange trees, in Brazil, causing reduced leaf size and fruit that are small and early maturing. Xylella fastidiosa, the pathogenic agent of CVC, presents in its genome an operon containing 9 genes (B,C,D,E,F,H,J,K,M) responsible for the biosynthesis of the exopolysaccharide denoted xyleilan gum, that can be related to pathogenicity. Despite the synthesis of xyleilan gum is a complex process, the investigation of functionally of Gum operon and the structural studies of these enzymes will be an important tools for design of specific inhibitors and for further investigation of a possible disease contrai. In this work we propose clone, express, purify, crystallize and solve the structure three-dimensional of these enzymes. Seven genes (B,C,D,F,H,K,M) involved in xyleilan gum biosynthesis have been cloned in expression vectors. At the present three enzymes (gumC, gumD, gumH) were expressed in E. coli, in a soluble form, and are in final purification step. One of them (gumC), with a high purification degree, is been submitted at crystallization experiments. (AU)