The lkyB gene of Escherichia coli K12 has been cloned from the Clarke and Carbon colony bank by selecting a ColEa plasmid conferring cholic acid resistance to lkyB mutants. The lkyB gene was localized on hybrid plasmid pJC778 by analysis of mutated plasmids generated by Tn5 insertions. Restriction a
Regulation of the lkyB gene expression in Escherichia coli K-12 strains carrying an lkyB-lacZ gene fusion
โ Scribed by Lazzaroni, Jean Claude ;Portalier, Raymond C.
- Publisher
- Springer
- Year
- 1985
- Tongue
- English
- Weight
- 742 KB
- Volume
- 201
- Category
- Article
- ISSN
- 0026-8925
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โฆ Synopsis
Phage MudII301 was used to isolate new periplasmic-leaky mutants of Escherichia coli K12 carrying an lkyB-lacZ gene fusion. The properties of strain JC2299 carrying the lkyB-2299 insertion mutation were identical to those of strain JC207 carrying the previously described lkyB-207 mutation. The LkyB-beta-galactosidase hybrid protein was partially extracellular and membrane bound. It was shown that both a nonsense (envZ-22) and a polar (ompR::Tn10) mutation in the ompB operon led to an increase of beta-galactosidase activity in the lkyB-lacZ fusion strain. On the other hand, mutations in the phoB, phoR, phoS, phoT, malT or envY genes had no effect on lkyB gene expression.
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