Single-site chromosomal Tn5 insertions affect the export of pectolytic and cellulolytic enzymes in Erwinia chrysanthemi EC16.
AUTOR(ES)
Thurn, K K
RESUMO
Exponentially growing cells of Erwinia chrysanthemi EC16 usually export about 98% of their pectate lyase (PL) and protease, about 40% of their polygalacturonase (PG), and about 60% of their cellulase (endoglucanase or carboxymethyl cellulase; CL). By using the R plasmid, pJB4JI (pPH1JI::Mu::Tn5), three independent Tn5 insertion mutants were obtained that exported normal levels of protease but 10% or less of PL, PG, and CL. Physical analysis revealed that single copies of Tn5 had inserted into the E. chrysanthemi chromosome, producing a similar export-defective (Out-) phenotype. The synthesis of PL, PG, and CL was not affected by the Tn5 insertions. These enzymes were released from the mutants on spheroplast formation, indicating that they were located in the periplasmic space. Tn5 insertions caused the loss of a 35-kilodalton periplasmic protein, but did not alter the outer membrane protein composition. The findings are discussed with respect to the current knowledge on protein export in gram-negative bacteria.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=296101Documentos Relacionados
- Uptake of galacturonic acid in Erwinia chrysanthemi EC16.
- Structure and organization of the pel genes from Erwinia chrysanthemi EC16.
- Cloning of genes encoding extracellular metalloproteases from Erwinia chrysanthemi EC16.
- Differential depolymerization mechanisms of pectate lyases secreted by Erwinia chrysanthemi EC16.
- Interruption-deficient mutants of bacteriophage T5: analysis of single-site mutants.