Disease relevance of bglB

• Escherichia coli K12 does not metabolize beta-glucosides such as arbutin and salicin because of lack of expression of the bglBSRC operon, which contains structural genes for transport (bglC) and hydrolysis (bglB) of phospho-beta-glucosides [1].
• Similarly, Proteus mirabilis, Enterobacter aerogenes and a non-enteric Gram-negative bacterium Pseudomonas aeruginosa have been shown to carry a homolog of the bglR and bglG regions and deletions of the bglF and bglB genes [2].
• The nucleotide sequence of the bglB gene, coding for the thermostable beta-glucosidase B of Clostridium thermocellum was determined [3].
• Thermotoga neapolitana bglB gene, upstream of lamA, encodes a highly thermostable beta-glucosidase that is a laminaribiase [4].
• The Klebsiella equivalents of bglG, bglB and bglR have been cloned using the genome sequence database of Klebsiella pneumoniae [5].

High impact information on bglB

• The transducing phages had been isolated from a strain of E. coli carrying prophage lambda cI857 S7 within the bglB gene located near the unc gene cluster [Miki, T., Hiraga, S., Nagata, T. & Yura, T. (1978) Proc. Natl. Acad. Sci. USA 75, 5099--5103] [6].
• Utilization of beta-glucosides in bglY mutants appeared to be a consequence of expression of the bglBSRC operon, since bglB bglR and bglB bglY double mutants had the same phenotype [1].
• Restriction endonuclease analysis and sequence data revealed that the clones could be divided into two groups, bglA and bglB, which were shown to be genetically distinct by Southern hybridization analyses [7].
• Sequence data from both cDNA and genomic clones showed the absence of introns in bglB [7].
• The DNA sequence of the 2.2-kb insert carrying bglB has been determined [8].

Chemical compound and disease context of bglB

• A plasmid carrying the blgA gene inserted in vector pUC18 was mutagenized in vitro with hydroxylamine, and subsequently used to transform E. coli selecting for the ampicillin resistance conferred by the cloning vector [9].

Biological context of bglB

• We have defined the extent and location of three structural genes, bglC, bglS, and bglB, and have determined their DNA sequence [10].
• Based on the ability of cloned regions of the operon to complement a series of Bgl- point mutations, we show that the three bgl structural genes, bglC, bglS, and bglB, are located downstream of the regulatory locus bglR in the order indicated [11].
• As a result, mutational activation of the silent bgl promoter confers an Arbutin-positive (Arb(+)) phenotype to the cells in a single step; however, acquiring a Salicin-positive (Sal(+)) phenotype requires the reversion or suppression of the bglB mutation in addition [12].
• A locus, designated het, which in its diploid state results in slow growth and heterogeneity of cell size due to distorted cell division, maps between bglB and asn, 30-45 kb counterclockwise of ilv [13].
• Sequence analysis of the 5,557 bp cloned DNA fragment (accession no. AY542524) showed three open reading frames (bglT, bglP, and bglB) predicted to encode 287, 633, and 468 amino acid proteins respectively [14].

Anatomical context of bglB

• We have now found that F' merodiploid strains containing two copies of the DNA between bglB and ilv have increased levels of this protein and an increased amount of DNA in their outer membranes [15].

Associations of bglB with chemical compounds

• Because of its unique ability to tolerate end-product inhibition by glucose, the bglB gene that encodes this enzyme was previously cloned and sequenced in this laboratory [16].

Analytical, diagnostic and therapeutic context of bglB

• Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting of cell lysates from Escherichia coli bglB clones confirmed the presence of an expressed protein with an apparent molecular mass of 72 kDa, which is consistent with that expected for an unglycosylated form of the enzyme [7].

References