The Bacillus stearothermophilus argCJBD operon harbours a strong promoter as evaluated in Escherichia coli cells.
We have shown that the B. stearothermophilus argCJBD genes form a single operon. In B. stearothermophilus, a specific repressor governs operon expression by binding to the argCo operator site overlapping the Parg promoter sequence (Dion et al., 1997). Therefore, the enzymatic and transcriptional analyses performed in this work did not reflect the potential strength of Parg in the native host. For evaluation of the Parg promoter strength, E. coli was used as a host since its own ArgR repressor does not interact with the B. stearothermophilus heterologous operator. Parg-promoted argC gene expression dramatically increased, reaching up to 38% of the total protein in E. coli cells. An AT-rich sequence upstream of a -35 site of Parg was found to be indispensable for the promoter strength. Plasmids carrying the B. stearothermophilus argCJBD operon linked with its Parg/argCo region were unstable in E. coli. Stabilization of plasmids was achieved by repression of B. stearothermophilus arg genes through the action of the B. subtilis AhrC repressor.
Savchenko
A
A
Unité de Recherche sur la Biocatalyse, Laboratoire de Biotechnologie, Faculté des Sciences et des Techniques, Université de Nantes, 2, rue de la Houssinière, F-44322, Nantes, Cedex 03, France.
Weigel
P
P
Dimova
D
D
Lecocq
M
M
Sakanyan
V
V
D000123:Acetyltransferases / Q000235:genetics*; D000445:Aldehyde Oxidoreductases; D001120:Arginine / Q000235:genetics*; D001412:Bacillus subtilis / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D001411:Geobacillus stearothermophilus / Q000235:genetics*; D034982:Integration Host Factors; D008969:Molecular Sequence Data; D009876:Operon / Q000235:genetics; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid
D001426:Bacterial Proteins; D034982:Integration Host Factors; D001120:Arginine; D000445:Aldehyde Oxidoreductases; C089846:argC protein, Bacteria; D000123:Acetyltransferases; C020646:glutamate acetyltransferase