The mature portion of Escherichia coli maltose-binding protein (MBP) determines the dependence of MBP on SecB for export.
AUTOR(ES)
Gannon, P M
RESUMO
The product of the secB gene is required for export of a subset of secreted proteins to the outer membrane and periplasm of Escherichia coli. Precursor maltose-binding protein (MBP) accumulates in the cytoplasm of secB-carrying mutants, but export of alkaline phosphatase is only minimally affected by secB mutations. When export of MBP-alkaline phosphatase hybrid proteins was analyzed in wild-type and secB-carrying mutant strains, the first third of mature MBP was sufficient to render export of the hybrid proteins dependent on SecB. Substitution of a signal sequence from a SecB-independent protein had no effect on SecB-dependent export. These findings show that the first third of mature MBP is capable of conferring export incompetence on an otherwise competent protein.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=209669Documentos Relacionados
- SecB-independent export of Escherichia coli ribose-binding protein (RBP): some comparisons with export of maltose-binding protein (MBP) and studies with RBP-MBP hybrid proteins.
- prlA suppression of defective export of maltose-binding protein in secB mutants of Escherichia coli.
- Mutations that improve export of maltose-binding protein in SecB- cells of Escherichia coli.
- Escherichia coli sec mutants accumulate a processed immature form of maltose-binding protein (MBP), a late-phase intermediate in MBP export.
- Expression of Escherichia coli SecB in Bacillus subtilis facilitates secretion of the SecB-dependent maltose-binding protein of E. coli.