Structure and properties of the phosphoenolpyruvate: glucose phosphotransferase system of oral streptococci

1984 ◽  
Vol 30 (4) ◽  
pp. 495-502 ◽  
Author(s):  
Christian Vadeboncoeur
Keyword(s):  
Streptococcus Mutans ◽  
Soluble Factor ◽  
Oral Streptococci ◽  
Structure And Properties ◽  
Streptococcus Salivarius ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Mutant Cells ◽  
Enzyme I ◽  
Negative Mutant

The presence of three distinct enzymes II that catalysed the phosphoenolpyruvate-dependent phosphorylation of glucose, fructose, and mannose was established in membranes of glucose-grown cells of Streptococcus salivarius 25975 and various strains of Streptococcus mutans. The enzyme II mannose phosphorylated mainly mannose, glucose, and 2-deoxyglucose, and the enzyme II glucose phosphorylated glucose, α-methylglucoside, and 2-deoxyglucose. The phosphoenolpyruvate-dependent phosphorylation of glucose and α-methylglucoside by isolated membrane of wild-type or EII mannose negative mutant cells did not require the presence of any soluble protein other than enzyme I and the phosphocarrier protein HPr. This result suggested that oral streptococci do not possess a soluble factor III glucose. The enzyme II activities varied as a function of the growth sugar but were not coordinately regulated. The variation elicited by specific sugars was not identical for all the strains tested. Nevertheless, in the case of the S. mutans strains, growth at the expense of lactose always caused a significant decrease in the level of enzyme II activities. Finally, experiments conducted with EII mannose negative mutants and also with a pseudorevertant isolated from one of these mutants indicated that the preferential utilization of glucose over lactose by cells growing in mixtures depended on the presence of the EII mannose, but not on glucose-derived metabolites.

scholarly journals Characterization of Streptococcus mutans Strains Deficient in EIIABMan of the Sugar Phosphotransferase System

2003 ◽  
Vol 69 (8) ◽  
pp. 4760-4769 ◽  
Author(s):  
Jacqueline Abranches ◽  
Yi-Ywan M. Chen ◽  
Robert A. Burne
Keyword(s):  
Streptococcus Mutans ◽  
Type Strain ◽  
Wild Type Strain ◽  
Sugar Transport ◽  
Fold Increase ◽  
Sugar Uptake ◽  
Uptake System ◽  
Oral Streptococci ◽  
Wild Type ◽  
Phosphotransferase System

ABSTRACT The phosphoenolpyruvate:sugar phosphotransferase system (PTS) is the major sugar uptake system in oral streptococci. The role of EIIABMan (encoded by manL) in gene regulation and sugar transport was investigated in Streptococcus mutans UA159. The manL knockout strain, JAM1, grew more slowly than the wild-type strain in glucose but grew faster in mannose and did not display diauxic growth, indicating that EIIABMan is involved in sugar uptake and in carbohydrate catabolite repression. PTS assays of JAM1, and of strains lacking the inducible (fruI) and constitutive (fruCD) EII fructose, revealed that S. mutans EIIABMan transported mannose and glucose and provided evidence that there was also a mannose-inducible or glucose-repressible mannose PTS. Additionally, there appears to be a fructose PTS that is different than FruI and FruCD. To determine whether EIIABMan controlled expression of the known virulence genes, glucosyltransferases (gtfBC) and fructosyltransferase (ftf) promoter fusions of these genes were established in the wild-type and EIIABMan-deficient strains. In the manL mutant, the level of chloramphenicol acetyltransferase activity expressed from the gtfBC promoter was up to threefold lower than that seen with the wild-type strain at pH 6 and 7, indicating that EIIABMan is required for optimal expression of gtfBC. No significant differences were observed between the mutant and the wild-type background in ftf regulation, with the exception that under glucose-limiting conditions at pH 7, the mutant exhibited a 2.1-fold increase in ftf expression. Two-dimensional gel analysis of batch-grown cells of the EIIABMan-deficient strain indicated that the expression of at least 38 proteins was altered compared to that seen with the wild-type strain, revealing that EIIABMan has a pleiotropic effect on gene expression.

The phosphoenolpyruvate: sugar phosphotransferase system of Streptococcus salivarius. Identification of a IIIman protein

1987 ◽  
Vol 33 (2) ◽  
pp. 118-122 ◽  
Author(s):  
Christian Vadeboncoeur ◽  
Lucie Gauthier
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Deae Cellulose ◽  
Reaction Medium ◽  
Inhibitory Effect ◽  
Spontaneous Mutant ◽  
Streptococcus Salivarius ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Growth Inhibitory

A double-spontaneous mutant resistant to the growth inhibitory effect of α-methylglucoside and 2-deoxyglucose was isolated from Streptococcus salivarius. This mutant strain, called αS3L11, did not grow on mannose and grew poorly on 5 mM fructose and 5 mM glucose. Isolated membranes of strain αS3L11 were unable to catalyse the phosphoenolpyruvate-dependent phosphorylation of mannose in the presence of purified enzyme I and HPr. Addition of dialysed membrane-free cellular extract of the wild-type strain to the reaction medium restored the activity. The factor that restored the phosphoenolpyruvate–mannose phosphotransferase activity to membranes of strain αS3L11 was called IIIman. This factor was partially purified from the wild-type strain by DEAE-cellulose chromatography, DEAE-TSK chromatography, and molecular seiving on a column of Ultrogel AcA 34. This partially purified preparation also enhanced the phosphoenolpyruvate-dependent phosphorylation of glucose, fructose, and 2-deoxyglucose in strain αS3L11.

Phosphoenolpyruvate-Dependent Glucose Transport in Oral Streptococci

1973 ◽  
Vol 52 (6) ◽  
pp. 1209-1215 ◽  
Author(s):  
Charles F. Schachtele ◽  
John A. Mayo
Keyword(s):  
Glucose Uptake ◽  
Streptococcus Mutans ◽  
Glucose Transport ◽  
Enzyme System ◽  
Cell Suspensions ◽  
Oral Streptococci ◽  
Phosphotransferase System ◽  
Resting Cell

Streptococcus mutans, S sanguis, and S salivarius use a phosphoenolpyruvate (PEP)-dependent phosphotransferase system that results in phosphorylation of glucose at carbon 6. This enzyme system is not sensitive to fluoride. Glucose uptake into resting cell suspensions is sensitive to fluoride because of inhibition of intracellular PEP production. The glucose phosphotransferase system is constitutive in oral streptococci.

scholarly journals Phenotypic Consequences Resulting from a Methionine-to-Valine Substitution at Position 48 in the HPr Protein of Streptococcus salivarius

1999 ◽  
Vol 181 (22) ◽  
pp. 6914-6921 ◽  
Author(s):  
Pascale Plamondon ◽  
Denis Brochu ◽  
Suzanne Thomas ◽  
Julie Fradette ◽  
Lucie Gauthier ◽  
...  
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Minor Effect ◽  
Streptococcus Salivarius ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Gene Encoding ◽  
Regulatory Molecule ◽  
Dependent Protein ◽  
A Minor

ABSTRACT In gram-positive bacteria, the HPr protein of the phosphoenolpyruvate:sugar phosphotransferase system (PTS) can be phosphorylated on a histidine residue at position 15 (His15) by enzyme I (EI) of the PTS and on a serine residue at position 46 (Ser46) by an ATP-dependent protein kinase (His∼P and Ser-P, respectively). We have isolated fromStreptococcus salivarius ATCC 25975, by independent selection from separate cultures, two spontaneous mutants (Ga3.78 and Ga3.14) that possess a missense mutation in ptsH (the gene encoding HPr) replacing the methionine at position 48 by a valine. The mutation did not prevent the phosphorylation of HPr at His15 by EI nor the phosphorylation at Ser46 by the ATP-dependent HPr kinase. The levels of HPr(Ser-P) in glucose-grown cells of the parental and mutant Ga3.78 were virtually the same. However, mutant cells growing on glucose produced two- to threefold less HPr(Ser-P)(His∼P) than the wild-type strain, while the levels of free HPr and HPr(His∼P) were increased 18- and 3-fold, respectively. The mutants grew as well as the wild-type strain on PTS sugars (glucose, fructose, and mannose) and on the non-PTS sugars lactose and melibiose. However, the growth rate of both mutants on galactose, also a non-PTS sugar, decreased rapidly with time. The M48V substitution had only a minor effect on the repression of α-galactosidase, β-galactosidase, and galactokinase by glucose, but this mutation abolished diauxie by rendering cells unable to prevent the catabolism of a non-PTS sugar (lactose, galactose, and melibiose) when glucose was available. The results suggested that the capacity of the wild-type cells to preferentially metabolize glucose over non-PTS sugars resulted mainly from inhibition of the catabolism of these secondary energy sources via a HPr-dependent mechanism. This mechanism was activated following glucose but not lactose metabolism, and it did not involve HPr(Ser-P) as the only regulatory molecule.

The LicT protein acts as both a positive and a negative regulator of loci within the bgl regulon of Streptococcus mutans

Microbiology ◽  
2003 ◽  
Vol 149 (5) ◽  
pp. 1333-1340 ◽  
Author(s):  
Christopher K. Cote ◽  
Allen L. Honeyman
Keyword(s):  
Streptococcus Mutans ◽  
Dna Sequence ◽  
Transcriptional Activity ◽  
Wild Type Strain ◽  
Negative Regulator ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Reading Frame ◽  
Genomic Dna Sequence ◽  
Transcriptional Fusions

An open reading frame (ORF) that would encode a putative antiterminator protein (LicT) of the BglG family was identified in the genomic DNA sequence of Streptococcus mutans. A DNA sequence that would encode a potential ribonucleic antiterminator (RAT) site in the mRNA at which the putative antitermination protein LicT would bind was located immediately downstream from this ORF. These putative antitermination components are upstream of a glucose-independent β-glucoside-utilization system that is responsible for aesculin utilization by S. mutans NG8 in the presence of glucose. It was hypothesized that these putative regulatory components were an important mechanism that was involved with the controlled expression of the S. mutans bglP locus. A strain of S. mutans containing a licT : : Ω-Kan2 insertional mutation was created. This strain could not hydrolyse aesculin in the presence of glucose. The transcriptional activity associated with other genes from the bgl regulon was determined in the licT : : Ω-Kan2 genetic background using lacZ transcriptional fusions and β-galactosidase assays to determine the effect of LicT on these loci. The LicT protein had no significant effect on the expression of the bglC promoter, a regulator of the bglA locus. However, it is essential for the optimal expression of bglP. These data correlate with the phenotype observed on aesculin plates for the S. mutans wild-type strain NG8 and the licT : : Ω-Kan2 strain. Thus, the glucose-independent β-glucoside-specific phosphotransferase system (PTS) regulon in S. mutans relies on LicT for BglP expression and, in turn, aesculin transport in the presence of glucose. Interestingly, LicT also seems to negatively regulate the expression of the bglA promoter region. In addition, the presence of the S. mutans licT gene has been shown to be able to activate a cryptic β-glucoside-specific operon found in Escherichia coli.

scholarly journals Galactose Metabolism by Streptococcus mutans

2004 ◽  
Vol 70 (10) ◽  
pp. 6047-6052 ◽  
Author(s):  
Jacqueline Abranches ◽  
Yi-Ywan M. Chen ◽  
Robert A. Burne
Keyword(s):  
Streptococcus Mutans ◽  
Wild Type Strain ◽  
Sugar Metabolism ◽  
Growth Defect ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Galactose Metabolism ◽  
Gene Encoding ◽  
Leloir Pathway ◽  
In The Wild

ABSTRACT The galK gene, encoding galactokinase of the Leloir pathway, was insertionally inactivated in Streptococcus mutans UA159. The galK knockout strain displayed only marginal growth on galactose, but growth on glucose or lactose was not affected. In strain UA159, the sugar phosphotransferase system (PTS) for lactose and the PTS for galactose were induced by growth in lactose and galactose, although galactose PTS activity was very low, suggesting that S. mutans does not have a galactose-specific PTS and that the lactose PTS may transport galactose, albeit poorly. To determine if the galactose growth defect of the galK mutant could be overcome by enhancing lactose PTS activity, the gene encoding a putative repressor of the operon for lactose PTS and phospho-β-galactosidase, lacR, was insertionally inactivated. A galK and lacR mutant still could not grow on galactose, although the strain had constitutively elevated lactose PTS activity. The glucose PTS activity of lacR mutants grown in glucose was lower than in the wild-type strain, revealing an influence of LacR or the lactose PTS on the regulation of the glucose PTS. Mutation of the lacA gene of the tagatose pathway caused impaired growth in lactose and galactose, suggesting that galactose can only be efficiently utilized when both the Leloir and tagatose pathways are functional. A mutation of the permease in the multiple sugar metabolism operon did not affect growth on galactose. Thus, the galactose permease of S. mutans is not present in the gal, lac, or msm operons.

scholarly journals Different Roles of EIIABMan and EIIGlc in Regulation of Energy Metabolism, Biofilm Development, and Competence in Streptococcus mutans

2006 ◽  
Vol 188 (11) ◽  
pp. 3748-3756 ◽  
Author(s):  
Jacqueline Abranches ◽  
Melissa M. Candella ◽  
Zezhang T. Wen ◽  
Henry V. Baker ◽  
Robert A. Burne
Keyword(s):  
Energy Metabolism ◽  
Streptococcus Mutans ◽  
Energy Levels ◽  
Sugar Metabolism ◽  
Oral Streptococci ◽  
Phosphotransferase System ◽  
Exogenous Dna ◽  
Biofilm Development ◽  
Metabolism Gene

ABSTRACT The phosphoenolpyruvate:sugar phosphotransferase system (PTS) is the major carbohydrate transport system in oral streptococci. The mannose-PTS of Streptococcus mutans, which transports mannose and glucose, is involved in carbon catabolite repression (CCR) and regulates the expression of known virulence genes. In this study, we investigated the role of EIIGlc and EIIABMan in sugar metabolism, gene regulation, biofilm formation, and competence. The results demonstrate that the inactivation of ptsG, encoding a putative EIIGlc, did not lead to major changes in sugar metabolism or affect the phenotypes of interest. However, the loss of EIIGlc was shown to have a significant impact on the proteome and to affect the expression of a known virulence factor, fructan hydrolase (fruA). JAM1, a mutant strain lacking EIIABMan, had an impaired capacity to form biofilms in the presence of glucose and displayed a decreased ability to be transformed with exogenous DNA. Also, the lactose- and cellobiose-PTSs were positively and negatively regulated by EIIABMan, respectively. Microarrays were used to investigate the profound phenotypic changes displayed by JAM1, revealing that EIIABMan of S. mutans has a key regulatory role in energy metabolism, possibly by sensing the energy levels of the cells or the carbohydrate availability and, in response, regulating the activity of transcription factors and carbohydrate transporters.

Properties of phosphorylated protein intermediates of the bacterial phosphoenolpyruvate:sugar phosphotransferase system

1992 ◽  
Vol 70 (3-4) ◽  
pp. 242-246 ◽  
Author(s):  
J. W. Anderson ◽  
E. B. Waygood ◽  
M. H. Saier Jr. ◽  
J. Reizer
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Active Site ◽  
Active Sites ◽  
Sugar Transport ◽  
Wild Type ◽  
Phosphotransferase System ◽  
E Coli ◽  
Phosphorylated Protein ◽  
Enzyme I

The phosphohydrolysis properties of the following phosphoprotein intermediates of the bacterial phosphoenolpyruvate:sugar phosphotransferase system (PTS) were investigated: enzyme I, HPr, and the IIAGlc domain of the glucose enzyme II of Bacillus subtilis; and IIAGlc (fast and slow forms) of Escherichia coli. The phosphohydrolysis properties were also studied for the site-directed mutant H68A of B. subtilis IIAGlc. Several conclusions were reached. (i) The phosphohydrolysis properties of the homologous phosphoprotein intermediates of B. subtilis and E. coli are similar. (ii) These properties deviate from those of isolated Nδ1- and Nε2-phosphohistidine indicating the participation of neighbouring residues at the active sites of these proteins. (iii) The rates of phosphohydrolysis of the H68A mutant of B. subtilis IIAGlc were reduced compared with the wild-type protein, suggesting that both His-83 and His-68 are present at the active site of wild-type IIAGlc. (iv) The removal of seven N-terminal residues of E. coli IIAGlc reduced the rates of phosphohydrolysis between pH 5 and 8.Key words: phosphoenolpyruvate:sugar phosphotransferase system, phosphoproteins, phosphohistidine, phosphorylation, sugar transport.

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