In Escherichia coli biotin biosynthesis is repressed by high concentrations of exogenous biotin. This paper reports that upon high level production of the apo form of a biotinated protein, biotin operon expression was derepressed by 8-10-fold. The biotinated protein studied was the 1.3 S subunit of Propionibacterium shermanii, and transcarboxylase derepression was assayed by β-galactosidase production in strains which carry a lacZ gene altered such that it is transcribed from biotin operon promoters. Depression of β-galactosidase synthesis upon production of the apo 1.3 S protein was observed over a several hundred-fold range of biotin concentrations and also resulted in an increased level of biotin operon expression at maximally repressing biotin concentrations. Biotin operon derepression by apobiotin protein production seems a direct consequence of the properties of the biotin repressor protein which also functions as the ligase catalyzing the covalent attachment of biotin to apoproteins.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Biological Chemistry|
|State||Published - 1988|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology