Biochemical characterization of avirulent Agrobacterium tumefaciens chvA mutants: synthesis and excretion of beta-(1-2)glucan.

En:

J. Bacteriol. 1989;171(5):2842-2849

Fecha:

1989

Formato:

application/pdf

Tipo de documento:

info:eu-repo/semantics/article
info:ar-repo/semantics/artículo
info:eu-repo/semantics/publishedVersion

Descriptores:

carrier protein -  glucan -  membrane protein -  peptide fragment -  article -  cell membrane -  gel chromatography -  genetics -  metabolism

Descripción:

The chvA gene product of Agrobacterium tumefaciens is required for virulence and attachment of bacteria to plant cells. Three chvA mutants were studied. In vivo, they were defective in the synthesis, accumulation, and secretion of beta-(1-2)glucan; however, the 235-kilodalton (kDa) protein known to be involved in the synthesis of beta-(1-2)glucan (A. Zorreguieta and R. Ugalde, J. Bacteriol. 167:947-951, 1986) was present and active in vitro. was present and active in vitro. Two molecular forms of cyclic beta-(1-2)glucan, designated types I and II, were resolved by gel chromatography. Type I beta-(1-2)glucan was substituted with nonglycosidic residues, and type II beta-(1-2)glucan was nonsubstituted. Wild-type cells accumulated type I beta-(1-2)glucan, and chvA mutant cells accumulated mainly type II beta-(1-2)glucan and a small amount of type I beta-(1-2)glucan. Inner membranes of wild-type and chvA mutants formed in vitro type II nonsubstituted beta-(1-2)glucan. A 75-kDa inner membrane protein is proposed to be the chvA gene product. chvA mutant inner membranes had increased levels of 235-kDa protein; partial trypsin digestion patterns suggested that the 235-kDa protein (the gene product of the chvB region) and the gene product of the chvA region form a complex in the inner membrane that is involved in the synthesis, secretion, and modification of beta-(1-2)glucan. All of the defects assigned to the chvA mutation were restored after complementation with plasmid pCD522 containing the entire chvA region.
Fil:Ugalde, R.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

Identificador(es):

http://hdl.handle.net/20.500.12110/paper_00219193_v171_n5_p2842_deIannino

Derechos:

info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/2.5/ar