Uhland, Kerstin; Ehrle, Rainer; Zander, Thomas; Ehrmann, Michael:
Requirements for translocation of periplasmic domains in polytopic membrane proteins
1994
In: Journal of bacteriology : JB, Jg. 176 (1994), Heft 15, S. 4565 - 4571
Artikel/Aufsatz in Zeitschrift / Fach: Biologie
Fakultät für Biologie
Titel:
Requirements for translocation of periplasmic domains in polytopic membrane proteins
Autor(in):
Uhland, Kerstin; Ehrle, Rainer; Zander, Thomas; Ehrmann, Michael im Online-Personal- und -Vorlesungsverzeichnis LSF anzeigen
Erscheinungsjahr
1994
Erschienen in:
Journal of bacteriology : JB, Jg. 176 (1994), Heft 15, S. 4565 - 4571
ISSN
Signatur der UB
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Abstract:

Periplasmic domains of cytoplasmic membrane proteins require export signals for proper translocation. These signals were studied by using a MalF- alkaline phosphatase fusion in a genetic selection that allowed the isolation of mislocalization mutants. In the original construct, alkaline phosphatase is fused to the second periplasmic domain of the membrane protein, and its activity is thus confined exclusively to the periplasm. Mutants that no longer translocated alkaline phosphatase were selected by complementation of a serB mutation. A total of 11 deletions in the amino terminus were isolated, all of which spanned at least the third transmembrane segment. This domain immediately precedes the periplasmic domain to which alkaline phosphatase was fused. Our results obtained in vivo support the model that amino-terminal membrane-spanning segments are required for translocation of large periplasmic domains. In addition, we found that the inability to export the alkaline phosphatase domain could be suppressed by a mutation, prlA4, in the secretion apparatus.