ISSN:
0730-2312
Keywords:
leucine binding protein
;
protein secretion
;
proteolysis
;
degradation
;
site-directed mutagenesis
;
membrane potential
;
processing
;
periplasmic proteins
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
The leucine-specific binding protein (LS-BP), a periplasmic component of the Escherichia coli high-affinity leucine transport system, is initially synthesized in a precursor form with a 23 amino acid N-terminal leader sequence that is removed during secretion of the protein into the periplasm. Using in vitro mutagenesis, deletion mutants of the LS-BP gene have been constructed with altered or missing amino acid sequences in the C-terminal portion of the protein. These altered binding proteins exhibited normal processing and secretion but were rapidly degraded in the periplasmic space. In the presence of an uncoupler of the transmembrane potential (CCCP) the precursor forms accumulated in the membrane and were protected from degradation. The altered binding proteins also were secreted by spheroplasts of E coli, after which they were easily detected.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcb.240240404
