• Korean Journal of Microbiology
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• v.25 no.3
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• pp.184-188
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• 1987

Evidences that the mannose permease of Escherichia coli mediates the infection of N4 in early steps, were obtained as follows. First, A mutant strain of Escherichia coli which was resistant to both wild type N4 and lambda whose genome is Charon 4A containing human genomic fragments in its EcoR I site, could not use mannose efficiently. Second, N4 could not infect pel mutant strains which lack one or all of intact components of mannose permease. However, unknown alterations in N4 made it possible for the phage to infect pel mutant of E. coli. It also turned out to be clear that the receptor of N4 was different from that of lambda.

• Journal of Microbiology and Biotechnology
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• v.5 no.4
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• pp.188-193
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• 1995

A Brevibacterium flavum gene coding for glucose permease of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) was cloned by complementing the Escherichia coli ZSCl13 mutations affecting a ptsG gene with the B. flavum genomic library. From the E. coli clone grown as red colony on a MacConkey plate supplemented with glucose as an additional carbon source, a recombinant plasmid was isolated and named pBFT93. The plasmid pBFT93 was identified as carrying a 3.6-kb fragment of B. flavum chromosomal DNA which enables the E. coli transformant to use glucose or man nose as a sole carbon source in an M9 minimal medium. The non-metabolizable sugar analogues, 2-deoxy-D-glucose (2-DG) and methyl-$\alpha$-D-glucopyranoside (MeGlc) affected the growth of ZSCl13 cells carrying the plasmid pBFT93 on minimal medium supplemented with non-PTS carbohydrate, glycerol, as a sole cabon source, while the analogues did not repress the growth of ZSCl13 cells without pBFT93. It was also found that both $2-deoxy-D-[U-^{14}C]glucose{\;}and{\;}methyl-{\alpha}-D-[U-^{14}C]glucopyranoside$ could be effectively transported into ZSCl13 cells transformed with plasmid pBFT93. Several in vivo complementation studies suggested that the B. flavum DNA in pBFT93 encodes a glucose permease specific for glucose and mannose.

• Journal of Microbiology and Biotechnology
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• v.8 no.3
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• pp.214-221
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• 1998

A Brevibacterium ammoniagenes gene coding for glucose/mannose-specific enzyme II ($EII^{Glc}$) of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) was cloned by complementing an Escherichia coli mutation affecting a ptsG gene, and the complete DNA nucleotide sequence was determined. The cloned gene was identified to be a ptsG, which enables the E. coli transportment to use glucose more efficiently than mannose as the sole carbon source in an M9 minimal medium. The ptsG gene of B. ammoniagenes consists of an open reading frame of 1,983 nucleotides putatively encoding a polypeptide of 661 amino acid residues and a TAA stop codon. The deduced amino acid sequence of the B. ammoniagenes $EII^{Glc}$ shows, at $46\%$, the highest degree of sequence similarity with the Corynebacterium glutamicum EII specific for both glucose and mannose. In addition, the $EII^{Glc}$ shares approximately $30\%$ sequence similarities with sucrose-specific and ${\beta}$-glucoside-specific EIIs of the several bacteria belonging to the glucose-PTS class. The 161-amino-acid C-terminal sequence of $EII^{Glc}$ is also similar to that of E. coli enzyme $IIA^{Glc}$, specific for glucose ($EIIA^{Glc}$). The B. ammoniagenes $EII^{Glc}$ consists of three domains; a hydrophobic region (EIIC) and two hydrophilic regions (EIIA, EIIB). The arrangement of structural domains, IIBCA, of the $EII^{Glc}$ is identical to those of EIIs specific for sucrose or ${\beta}$-glucoside. While the domain IIA was removed from the B. ammoniagenes $EII^{Glc}$ the remaining domains IIBC were found to restore the glucose and mannose-utilizing capacity of E. coli mutant lacking $EII^{Glc}$ activity with $EIIA^{Glc}$ of the E. coli mutant. $EII^{Glc}$ contains a histidine residue and a cysteine residue which are putative phosphorylation sites for the protein.

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.582-588
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• 1999

A Brevibacterium lactofermentum gene coding for a glucose-specific permease of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) was cloned, by complementing an Escherichia coli mutation affecting a ptsG gene with the B. lactofermentum genomic library, and completely sequenced. The gene was identified as a ptsG, which enables an E. coli transformant to transport non-metabolizable glucose analogue 2-deoxyglucose (2DG). The ptsG gene of B. lactofermentum consists of an open reading frame of 2,025 nucleotides encoding a polypeptide of 674 amino acid residues and a TAA stop codon. The 3' flanking region contains two stem-loop structures which may be involved in transcriptional termination. The deduced amino acid sequence of the B. lactofermentum enzyme $II^{GIe}$ specific to glucose ($EII^{GIe}$) has a high homology with the Corynebacterium glutamicum enzyme $II^{Man}$ specific to glucose and mannose ($EII^{Man}$), and the Brevibacterium ammoniagenes enzyme $II^{GIc}$ specific to glucose ($EII^{GIc}$). The 171-amino-acid C-terminal sequence of the $EII^{Glc}$ is also similar to the Escherichia coli enzyme $IIA^{GIc}$ specific to glucose ($IIA^{GIc}$). It is interesting that the arrangement of the structural domains, IIBCA, of the B. lactofermentum $EII^{GIc}$ protein is identical to that of EIIs specific to sucrose or $\beta$-glucoside. Several in vivo complementation studies indicated that the B. lactofermentum $EII^{Glc}$ protein could replace both $EII^{ Glc}$ and $EIIA^{Glc}$ in an E. coli ptsG mutant or crr mutant, respectively.