Diversity of Transport Mechanisms in Bacteria

Poolman, Bert; Molenaar, Douwe; Konings, Wil N.

doi:10.1002/9783527616114.ch5

Cited by 12 publications

(19 citation statements)

References 265 publications

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“…A-007 [71,72], and many of the bacterial (multi)drug and antibiotic resistance secondary carrier proteins [10,14]. Lysine effiux by Corynebacterium glutamicum has been proposed to occur as lysine-OH-symport [73] which is energetically similar to lysine/H + antiport.…”

Section: Ii-e Electrogenic Solute~cation Antiport (mentioning

confidence: 99%

“…From the known primary structures of secondary transport proteins it is evident that these systems have less structural complexity than, for instance, the ATPases or the phosphoenolpyruvate:sugar phosphotransferase systems [10]. The molecular masses of most of these proteins fall in the range 40-55 kDa [16].…”

Section: Iv-a Primary Sequence and Secondary Structurementioning

confidence: 99%

“…The lipid bilayer forms a matrix in which energy-transducing enzymes/carrier proteins are embedded and by which specific solute concentration gradients can be generated and maintained. The diversity of systems which can translocate solutes across the bacterial cytoplasmic membrane has recently been reviewed [10].…”

Section: General Introductionmentioning

confidence: 99%

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Secondary solute transport in bacteria

Poolman

Konings

1993

Biochimica et Biophysica Acta (BBA) - Bioenergetics

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Section: Ii-e Electrogenic Solute~cation Antiport (mentioning

confidence: 99%

Section: Iv-a Primary Sequence and Secondary Structurementioning

confidence: 99%

See 1 more Smart Citation

Secondary solute transport in bacteria

Poolman

Konings

1993

Biochimica et Biophysica Acta (BBA) - Bioenergetics

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202

160

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“…When maltose is the substrate, the formation of intracellular glucose can be more rapid than the subsequent metabolism, which leads to excretion of glucose via the uniport system. In fermentative bacteria, an electrochemical proton gradient (proton motive force) can be generated by proton extrusion via F0F,-ATPase or by electrogenic secondary transport processes (16,18,19). Most frequently, secondary transport systems catalyze symport of solutes with protons or sodium ions (18,19).…”

mentioning

confidence: 99%

Mechanism of maltose uptake and glucose excretion in Lactobacillus sanfrancisco

et al. 1994

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Lactobaci&ls sanfrancisco LTH 2581 can use only glucose and maltose as sources of metabolic energy. In maltose-metabolizing cells ofL. sanfrancisco, approximately half of the internally generated glucose appears in the medium. The mechanisms of maltose (and glucose) uptake and glucose excretion have been investigated in cells and in membrane vesicles of L. sanfrancisco in which beef heart cytochrome c oxidase had been incorporated as a proton-motive-force-generating system. In the presence of ascorbate, N,N,N',N'-tetramethylp-phenylenediamine (TMPD), and cytochrome c, the hybrid membranes facilitated maltose uptake against a concentration gradient, but accumulation of glucose could not be detected. Similarly, in intact cells of L. sanfrancisco, the nonmetabolizable glucose analog at-methylglucoside was taken up only to the equilibration level. Selective dissipation of the components of the proton and sodium motive force in the hybrid membranes indicated that maltose is transported by a proton symport mechanism. Internal [14C]maltose could be chased with external unlabeled maltose (homologous exchange), but heterologous maltose/glucose exchange could not be detected. Membrane vesicles of L. sanfrancisco also catalyzed glucose efflux and homologous glucose exchange. These activities could not be detected in membrane vesicles of glucose-grown cells. The results indicate that maltose-grown cells of L. sanfrancisco express a maltose-H+ symport and glucose uniport system. When maltose is the substrate, the formation of intracellular glucose can be more rapid than the subsequent metabolism, which leads to excretion of glucose via the uniport system. In fermentative bacteria, an electrochemical proton gradient (proton motive force) can be generated by proton extrusion via F0F,-ATPase or by electrogenic secondary transport processes (16,18,19). Most frequently, secondary transport systems catalyze symport of solutes with protons or sodium ions (18,19). The proton or sodium motive force is then used to drive solute transport. However, some secondary transport proteins catalyze exclusively an antiport. Examples of this class of transport are the systems which couple the uptake of precursor molecules to the excretion of product (precursor/product antiport) (16, 18). The driving forces for these processes are supplied by the (electro)chemical gradients of both precursor and product. An example of such an antiport system is the arginine/ornithine antiporter which has been detected in several bacteria (6,17 (9,16,20).Lactobacillus sanfrancisco strains are the main organisms in sourdough starter preparations (1,11,23,27). The prevailing sugar in sourdough is maltose, which is formed during degradation of starch by oa-amylase. The metabolism of maltose in cells of L. sanfrancisco is initiated by cleavage of maltose to glucose and glucose-i-phosphate via a maltose phosphorylase (24). Glucose-i-phosphate and part of the free glucose are metabolized, whereas approximately half of the generated glucose is released into the external ...

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“…The genes encoding these proteins are clustered together with genes encoding an a-galactosidase (Aga), sucrose phosphorylase (GtfA), dextran glucosidase (DexB), and the Leloir pathway enzymes. Although the nature of the driving force of the Msm system has not been demonstrated biochemically, the sequence homology with other transport ATPases makes it IikeIy that uptake is directly energized by ATP (Poolman et al, 1992a Iy complement an Escherichia coli lacY mutation, and components of binding protein dependent transporters (David, 1992) it is tempting to speculate that a lactose transport ATPase is also present in this organism. The number of ATP molecules hydrolyzed per solute taken up by the transport ATPases is most Iikely 1-2 (Poolman et al, 1992a) which makes these transporters energetically expensive as compared to the ion-linked transporters, exchange systems and PTS (see below).…”

Section: Galactoside Transport Atpasesmentioning

confidence: 99%

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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Diversity of Transport Mechanisms in Bacteria

Cited by 12 publications

References 265 publications

Secondary solute transport in bacteria

Secondary solute transport in bacteria

Mechanism of maltose uptake and glucose excretion in Lactobacillus sanfrancisco

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

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