A physical and functional analysis of the newly-identified bglGPT operon of Lactobacillus plantarum

作者：Marasco R; Salatiello I; De Felice M; Sacco M^*

来源：FEMS Microbiology Letters, 2000, 186(2): 269-273.

DOI：10.1111/j.1574-6968.2000.tb09116.x

• Lactobacillus
• carbon-catabolite repression
• beta-glucosidase
• bglGPT operon

A newly-identified bbl/GPT 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.

• 出版日期2000-5-15