Expression of the bglH gene of Lactobacillus plantarum is controlled by carbon catabolite repression.
A newly identified bglH gene coding for a phospho-beta-glucosidase of Lactobacillus plantarum was isolated and expressed in Escherichia coli. The sequence analysis of the cloned DNA fragment showed an open reading frame encoding a 480-amino-acid protein with a calculated molecular mass of 53 kDa. The bglH gene was shown to be expressed on a monocistronic transcriptional unit. Its transcription was repressed 10-fold in L. plantarum cells grown on glucose compared to the beta-glucoside salicin as a sole carbon source. A catabolite-responsive element (CRE) spanning from -3 to +11 with respect to the transcriptional start point was found, and its functionality was assessed by mutational analysis. In vitro and in vivo DNA binding experiments suggested the occurrence of a DNA-protein complex at the CRE site, which would mediate glucose repression of bglH expression.
Marasco
R
R
Dipartimento di Chimica, Università degli Studi di Salerno, Italy.
Muscariello
L
L
Varcamonti
M
M
De Felice
M
M
Sacco
M
M
D000595:Amino Acid Sequence; D001483:Base Sequence; D001592:Benzyl Alcohols / Q000378:metabolism; D003001:Cloning, Molecular; D016384:Consensus Sequence; D004794:Enzyme Repression; D005798:Genes, Bacterial; D005947:Glucose / Q000378:metabolism; D005959:Glucosidases / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D005960:Glucosides; D007778:Lactobacillus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012333:RNA, Messenger / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D001592:Benzyl Alcohols; D005960:Glucosides; D012333:RNA, Messenger; D011994:Recombinant Proteins; C005696:salicin; D005959:Glucosidases; C066586:6-phospho-beta-glucosidase; D005947:Glucose