Regulation of sugar transport and metabolism in lactic acid bacteria

Thompson, John F.

doi:10.1016/0378-1097(87)90109-1

Cited by 69 publications

(97 citation statements)

References 44 publications

(84 reference statements)

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“…In addition to catalysing galactosidc uptake concomitant with phosphorylation of the sugar, IIBC of the lactose PTS is also believed to cata-[yse efflux (expulsion) of intraccllularly formed free galactosidcs [14,46]. This expulsion of galac tosides is phcnomenologically similar to that observed in the heterofermentative lactobacilli where a secondary transport mechanism has been implicated in the efflux of frec galactosides (scc above…”

Section: Pep" Sugar Phosphotrans[~rease Systemsmentioning

confidence: 94%

Energy transduction in lactic acid bacteria

Poolman

1993

FEMS Microbiology Reviews

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In the discovery of some general principles of energy transduction, lactic acid bacteria have played an important role. In this review, the energy transducing processes of lactic acid bacteria are discussed with the emphasis on the major developments of the past 5 years. This work not only includes the biochemistry of the enzymes and the bioenergetics of the processes, but also the genetics of the genes encoding the energy transducing proteins. The progress in the area of carbohydrate transport and metabolism is presented first. Sugar translocation involving ATP-driven transport, ion-linked cotransport, heterologous exchange and group translocation are discussed. The coupling of precursor uptake to product product excretion and the linkage of antiport mechanisms to the deiminase pathways of lactic acid bacteria is dealt with in the second section. The third topic relates to metabolic energy conservation by ehemiosmotic processes. There is increasing evidence that precursor/product exchange in combination with precursor decarboxy[ation allows bacteria to generate additional metabolic energy. In the final section transport ot nutrients and ions as well as mechanisms to excrete undesirable (toxic) compounds from the cells are discussed.

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Section: Pep" Sugar Phosphotrans[~rease Systemsmentioning

confidence: 94%

Energy transduction in lactic acid bacteria

Poolman

1993

FEMS Microbiology Reviews

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“…Although first described for Escherichia coli, this group translocation system is now recognized as the primary mechanism for sugar accumulation by many species from both gram-negative (21, 26) and gram-positive bacterial genera (15,30,42,44). In a series of sequential transfers of the high-energy phosphoryl moiety from PEP, this multicomponent system catalyzes the simultaneous translocation and phosphorylation of sugars into the cell (21,26,36).…”

Section: ؉mentioning

confidence: 99%

Purification from Fusobacterium mortiferum ATCC 25557 of a 6-phosphoryl-O-alpha-D-glucopyranosyl:6-phosphoglucohydrolase that hydrolyzes maltose 6-phosphate and related phospho-alpha-D-glucosides

et al. 1995

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6-Phosphoryl-O-␣-D-glucopyranosyl:6-phosphoglucohydrolase (6-phospho-␣-glucosidase) has been purified from Fusobacterium mortiferum ATCC 25557. p-Nitrophenyl-␣-D-glucopyranoside 6-phosphate (pNP␣Glc6P) served as the chromogenic substrate for detection and assay of enzyme activity. The O 2 -sensitive, metaldependent phospho-␣-glucosidase was stabilized during purification by inclusion of dithiothreitol and Mn 2؉ ion in chromatography buffers. Various 6-phosphoryl-O-␣-linked glucosides, including maltose 6-phosphate, pNP␣Glc6P, trehalose 6-phosphate, and sucrose 6-phosphate, were hydrolyzed by the enzyme to yield D-glucose 6-phosphate and aglycone moieties in a 1:1 molar ratio. 6-Phospho-␣-glucosidase (M r of ϳ49,000; pI of ϳ4.9) is activated by Fe 2؉, Mn 2؉, Co 2؉, and Ni 2؉, and the maximum rate of pNP␣Glc6P hydrolysis occurs at 40؇C within the pH range 7.0 to 7.5. The sequence of the first 32 amino acids of 6-phospho-␣-glucosidase exhibits 67% identity (90% similarity) to that deduced for the N terminus of a putative phospho-␤-glucosidase (designated ORF f212) encoded by glvG in Escherichia coli. Western blots involving highly specific polyclonal antibody against 6-phospho-␣-glucosidase and spectrophotometric analyses with pNP␣Glc6P revealed only low levels of the enzyme in glucose-, mannose-, or fructose-grown cells of F. mortiferum. Synthesis of 6-phospho-␣-glucosidase increased dramatically during growth of the organism on ␣-glucosides, such as maltose, ␣-methylglucoside, trehalose, turanose, and palatinose.A landmark in our understanding of carbohydrate dissimilation by microorganisms was established in 1964 by the serendipitous discovery of the phosphoenolpyruvate-dependent: sugar phosphotransferase system (PEP:PTS) by Saul Roseman and his colleagues (17, 35). Although first described for Escherichia coli, this group translocation system is now recognized as the primary mechanism for sugar accumulation by many species from both gram-negative (21, 26) and gram-positive bacterial genera (15,30,42,44). In a series of sequential transfers of the high-energy phosphoryl moiety from PEP, this multicomponent system catalyzes the simultaneous translocation and phosphorylation of sugars into the cell (21,26,36).The phosphorylated products of hexose-and polyol-specific PEP:PTSs may directly enter the energy-generating (fermentation) pathways of the organism. By contrast, further metabolism of intracellular disaccharide phosphates necessitates the initial cleavage of these compounds to yield the appropriate free and phosphorylated hexose moieties. Sugar-specific (and frequently inducible) hydrolases catalyze the cleavage of the O-glycosidic linkage of the various disaccharide phosphates. Several such enzymes have been described, including those responsible for the hydrolysis of 6-phospho-␤-galactosides (6, 14, 16), 6-phospho-␤-glucosides (38, 39, 48), sucrose 6-phosphate (sucrose 6P) (7,18,46), cellobiose 6P (22), and trehalose 6P (31).Reports of maltose-PEP:PTS activity have engendered debate (5, 12, 20, 28, 41, 49),...

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“…By replacing each of the histidine and cysteine residues of IIBC of the lactose PTS of Lb casei evidence has been obtained that also a single cysteine (Cys-384) mediates the final phosphoryl transfer to lactose (AIpert and Chassy, 1990). ln additionto catalyzing galactoside uptake concomitant with phosphorylation of the sugar, IIBC of the lactose PTS is also 93 believed to catalyze efflux (expulsion) of intracellularly formed free galactosides (Reizer et al, 1985;Thompson, 1987). This expulsion of galactosides is phenomenologically similar to that observed in the heterofermentative lactobacilli where a secondary transport mechanism has been implicated in the efflux of free galactosides (see above, ion-Iinked galactoside transporters and galactoside exchange).…”

Section: Pep:galactoside Phosphotrans-ferase Systems (Pts)mentioning

confidence: 87%

Biochemistry and molecular biology of galactoside transport and metabolism in lactic acid bacteria

Poolman

1993

Lait

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Summary -Until a few years ago the description of the pathways of transport and metabolism of galactosides in lactic acid bacteria was mainly phenomenological. Different transport and enzymatic activities had been detected but the individual components (proteins, enzymes) were largely unknown and the genes had not yet been isolated. In this paper 1will address the different transport mechanisms and metabolic pathways of galactosides in factic acid bacteria, and indicate the meleeular level at which these studies have evolved. The genes encoding galactosidetransport ATPases ion Iinked galactoside transporters and phosphoenolpyruvate:galactoside phosphotransferase systems (PTS) have been isolated and characterized from a number of lactic acid bacteria. In addition, the genes encoding subsequent steps of lactose (galactose) metabolism, ie those encoding the Leloir and Tagatose 6 phosphate pathway enzymes, have been characterized at a genetic and to some extent at a biochemical javel. The genes encoding the transport proteins and metabolic enzymes are often clustered in a single operon or regulon which allows co-ordinate expression of the polypeptides. Transport of galactosides has most been thoroughly studied in Streptococcus thermophi/us where the transport gene encodes a chimeric protein (LacS) that is composed of a carrier domain homofogous to various ion Iinked carbohydrate transporters and a hydrophilic domain hornologous to the liA phosphoryl transfer protein of various PTSs. LacS has been extracted from membrane vesicles and functionally reconstituted into proteoliposomes, and the energetics and kinetic mechanism of transport have been analyzed. lacS mediates galactoside H+ symport and galactoside exchange (eg lactose/galactose exchange) of which the latter reaction is highly favoured under physiological conditions. Details of the galactoside translocation pathway have been estabIished by studying mutant LacS proteins in which the galactoside movement is uncoupled from the H+ transport whereas the exchange reaction takes place normally. The data offer a rationale for the observed excretion of galactose by Gal-and Galt strains of S thermophilus under conditions of growth in the presence of excess lactose.

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Regulation of sugar transport and metabolism in lactic acid bacteria

Cited by 69 publications

References 44 publications

Energy transduction in lactic acid bacteria

Energy transduction in lactic acid bacteria

Purification from Fusobacterium mortiferum ATCC 25557 of a 6-phosphoryl-O-alpha-D-glucopyranosyl:6-phosphoglucohydrolase that hydrolyzes maltose 6-phosphate and related phospho-alpha-D-glucosides

Biochemistry and molecular biology of galactoside transport and metabolism in lactic acid bacteria

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