ACTIVE-TRANSPORT BY THE CSCB PERMEASE IN ESCHERICHIA-COLI K-12
Autor(en): | SAHINTOTH, M FRILLINGOS, S LENGELER, JW KABACK, HR |
Stichwörter: | Biochemistry & Molecular Biology; Biophysics; LAC CARRIER PROTEIN; LACTOSE PERMEASE; MEMBRANE; PURIFICATION | Erscheinungsdatum: | 1995 | Herausgeber: | ACADEMIC PRESS INC ELSEVIER SCIENCE | Journal: | BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS | Volumen: | 208 | Ausgabe: | 3 | Startseite: | 1116 | Seitenende: | 1123 | Zusammenfassung: | The cscB gene encoding a putative sucrose permease from Escherichia coli EC3132 [Bockmann, J., Heuel, H. & Lengeler, J. W. (1992) Mol. Gen. Genet. 235, 22-32] was placed under control of the lacZ promoter/operator and overexpressed. Cells of E. coli K-12 expressing cscB gene product from a high copy number plasmid accumulate sucrose against a concentration gradient with an apparent K-m of about 1 mM and a V-max of approximately 23 nmol/min/mg protein. In contrast, transport of lactose or melibiose is not observed. Epitope-tagging and immunological analysis reveal that concomitant with increased transport activity, a protein with an apparent M(r) of 33-34 kDa appears in the cytoplasmic membrane. The results provide direct support for the contention that the cscB gene encodes a sucrose permease and provide the basis for further molecular analysis. (C) 1995 Academic Press, Inc. |
ISSN: | 0006291X | DOI: | 10.1006/bbrc.1995.1449 |
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