Effects of total hydrophobicity and length of the hydrophobic domain of a signal peptide on in vitro translocation efficiency.
J Biol Chem
; 267(7): 4882-8, 1992 Mar 05.
Article
em En
| MEDLINE
| ID: mdl-1531659
The hydrophobic domain of the signal peptide of OmpF-Lpp, a model secretory protein, was systematically engineered so as to be composed of different lengths of polyleucine residues or polymers with alternate leucine and alanine residues, and the effects of the length and nature of the hydrophobic stretch on the rate of in vitro translocation were studied using everted membrane vesicles of Escherichia coli. The translocation reaction exhibited high substrate specificity as to the number of hydrophobic residues. The results suggest that the hydrophobic domain is recognized specifically by a component(s) of the secretory machinery rather than nonspecifically by the hydrophobic region of the membrane. The in vitro translocation thus demonstrated required SecA and ATP and was markedly enhanced upon imposition of the proton motive force, as in the case of secretory proteins possessing a natural signal peptide. The highest translocation rate was obtained with the octamer in the case of polyleucine-containing signal peptides, whereas it was the decamer in the case of ones containing both leucine and alanine. These results suggest that the total hydrophobicity of the hydrophobic region of the signal peptides is an important determinant of the substrate specificity.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Membrana Transportadoras
/
Proteínas Recombinantes de Fusão
/
Sinais Direcionadores de Proteínas
/
Proteínas de Escherichia coli
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
1992
Tipo de documento:
Article
País de afiliação:
Japão
País de publicação:
Estados Unidos