A physical and functional analysis of the newly-identified bglGPT operon of Lactobacillus plantarum.
A newly-identified bglGPT operon of Lactobacillus plantarum was isolated and expressed in Escherichia coli. The sequence analysis of the cloned DNA fragment showed three open reading frames encoding (i) a 237-amino acid protein (BglG), (ii) a 577-amino acid protein (BglP) and (iii) a 486-amino acid protein (BglT). BglG, BglP and BglT were shown to be homologous to the BglG family of transcriptional antiterminators, to permeases of the phosphoenolpyruvate-dependent phosphotransferase system and to beta-glucosidases, respectively. Complementation of E. coli mutant strains showed that BglP and BglT are a permease and a beta-glucosidase active on the beta-glucosides, 5-bromo-4-chloro-3-indolyl-beta-D-glucopyranoside and p-nitrophenyl-beta-D-glucoside, respectively. BglG was also shown to promote expression of a bglG-lacZ gene fusion in an E. coli bglG(-) background. A ribonucleic antiterminator sequence, the antiterminator-responsive cis-element and a 'catabolite responsive element', were found downstream of the transcriptional start point. Transcription of the operon was repressed 10-fold in L. plantarum cells grown on glucose as compared to ribose.
Marasco
R
R
Facoltà di Scienze MM, FF e NN, Università degli Studi del Sannio, via Caio Ponzio Telesino 11, 82100, Benevento, Italy.
Salatiello
I
I
De Felice
M
M
Sacco
M
M
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D007778:Lactobacillus / Q000235:genetics* / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D009876:Operon; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics*; D010957:Plasmids; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D001617:beta-Glucosidase / Q000235:genetics* / Q000378:metabolism
D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; D012329:RNA, Bacterial; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; C064872:antiterminator proteins, Bacteria; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C031629:phosphoenolpyruvate-glucose phosphotransferase; D001617:beta-Glucosidase