Induction and metabolite regulation of levanase synthesis in Bacillus subtilis.
Levanase expression in Bacillus subtilis was studied by using transcriptional and translational fusions. It was shown that the degradative products of levan or inulin and low concentrations of fructose were able to induce levanase expression. In the wild-type strain and in a constitutive overproducing sacL mutant, levanase synthesis was repressed by glucose or fructose. This catabolite repression was partially abolished in the derepressed alpha-amylase gra-26 mutant. The levanase gene (sacC) appears to be the distal gene of an operon transcribed from a fructose-inducible promoter. Deletion mapping experiments and primer extension analysis revealed a transcriptional start point located 2.7 kilobases upstream from the sacC gene. Two constitutive sacL mutations were shown to be closely linked by transformation to the sacC gene. The sacL6 and sacL8 mutations were mapped in the promoter-proximal region of the operon.
Martin
I
I
Département des Biotechnologies, Institut Pasteur, Paris, France.
Debarbouille
M
M
Klier
A
A
Rapoport
G
G
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D004794:Enzyme Repression; D005632:Fructose / Q000378:metabolism; D005786:Gene Expression Regulation; D006026:Glycoside Hydrolases / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D011993:Recombinant Fusion Proteins / Q000235:genetics; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D005632:Fructose; D006026:Glycoside Hydrolases; C021512:levanase