-
World Journal of Microbiology &... Jul 2020The phosphoenolpyruvate-dependent glucose phosphotransferase system (PTS) is the major uptake system responsible for transporting glucose, and is involved in glucose... (Review)
Review
The phosphoenolpyruvate-dependent glucose phosphotransferase system (PTS) is the major uptake system responsible for transporting glucose, and is involved in glucose translocation and phosphorylation in Corynebacterium glutamicum. For the longest time, the PTS was considered as the only uptake system for glucose. However, some PTS-independent glucose uptake systems (non-PTS) were discovered in recent years, such as the coupling system of inositol permeases and glucokinases (IPGS) and the coupling system of β-glucoside-PTS permease and glucokinases (GPGS). The products (e.g. lysine, phenylalanine and leucine) will be increased because of the increasing intracellular level of phosphoenolpyruvate (PEP), while some by-products (e.g. lactic acid, alanine and acetic acid) will be reduced when this system become the main uptake pathway for glucose. In this review, we survey the uptake systems for glucose in C. glutamicum and their composition. Furthermore, we summarize the latest research of the regulatory mechanisms among these glucose uptake systems. Detailed strategies to manipulate glucose uptake system are addressed based on this knowledge.
Topics: Bacterial Proteins; Biological Transport; Carbohydrate Metabolism; Corynebacterium glutamicum; Glucose; Glucosides; Membrane Proteins; Membrane Transport Proteins; Mutagenesis, Site-Directed; Phosphoenolpyruvate Sugar Phosphotransferase System; Protein Kinases
PubMed: 32712859
DOI: 10.1007/s11274-020-02898-z -
Molecular Biology of the Cell Jun 1998Addition of ammonium ions to yeast cells growing on proline as the sole nitrogen source induces rapid inactivation and degradation of the general amino acid permease...
Addition of ammonium ions to yeast cells growing on proline as the sole nitrogen source induces rapid inactivation and degradation of the general amino acid permease Gap1 through a process requiring the Npi1/Rsp5 ubiquitin (Ub) ligase. In this study, we show that NH4+ induces endocytosis of Gap1, which is then delivered into the vacuole where it is degraded. This down-regulation is accompanied by increased conversion of Gap1 to ubiquitinated forms. Ubiquitination and subsequent degradation of Gap1 are impaired in the npi1 strain. In this mutant, the amount of Npi1/Rsp5 Ub ligase is reduced >10-fold compared with wild-type cells. The C-terminal tail of Gap1 contains sequences, including a di-leucine motif, which are required for NH4+-induced internalization and degradation of the permease. We show here that mutant Gap1 permeases affected in these sequences still bind Ub. Furthermore, we provide evidence that only a small fraction of Gap1 is modified by Ub after addition of NH4+ to mutants defective in endocytosis.
Topics: Amino Acid Sequence; Amino Acid Transport Systems; Animals; Endocytosis; Endosomal Sorting Complexes Required for Transport; Fungal Proteins; Ligases; Membrane Transport Proteins; Molecular Sequence Data; Nitrogen; Quaternary Ammonium Compounds; Rabbits; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Ubiquitin-Protein Ligase Complexes; Ubiquitin-Protein Ligases; Ubiquitins; Vacuoles
PubMed: 9614172
DOI: 10.1091/mbc.9.6.1253 -
Proceedings of the National Academy of... Dec 1997Sugar transport by some permeases in Escherichia coli is allosterically regulated by the phosphorylation state of the intracellular regulatory protein, enzyme IIAglc of...
Sugar transport by some permeases in Escherichia coli is allosterically regulated by the phosphorylation state of the intracellular regulatory protein, enzyme IIAglc of the phosphoenolpyruvate:sugar phosphotransferase system. A sensitive radiochemical assay for the interaction of enzyme IIAglc with membrane-associated lactose permease was used to characterize the binding reaction. The binding is stimulated by transportable substrates such as lactose, melibiose, and raffinose, but not by sugars that are not transported (maltose and sucrose). Treatment of lactose permease with N-ethylmaleimide, which blocks ligand binding and transport by alkylating Cys-148, also blocks enzyme IIAglc binding. Preincubation with the substrate analog beta-D-galactopyranosyl 1-thio-beta-D-galactopyranoside protects both lactose transport and enzyme IIAglc binding against inhibition by N-ethylmaleimide. A collection of lactose permease replacement mutants at Cys-148 showed, with the exception of C148V, a good correlation of relative transport activity and enzyme IIAglc binding. The nature of the interaction of enzyme IIAglc with the cytoplasmic face of lactose permease was explored. The N- and C-termini, as well as five hydrophilic loops in the permease, are exposed on the cytoplasmic surface of the membrane and it has been proposed that the central cytoplasmic loop of lactose permease is the major determinant for interaction with enzyme IIAglc. Lactose permease mutants with polyhistidine insertions in cytoplasmic loops IV/V and VI/VII and periplasmic loop VII/VIII retain transport activity and therefore substrate binding, but do not bind enzyme IIAglc, indicating that these regions of lactose permease may be involved in recognition of enzyme IIAglc. Taken together, these results suggest that interaction of lactose permease with substrate promotes a conformational change that brings several cytoplasmic loops into an arrangement optimal for interaction with the regulatory protein, enzyme IIAglc. A topological map of the proposed interaction is presented.
Topics: Allosteric Regulation; Allosteric Site; Amino Acid Sequence; Carbohydrates; Escherichia coli; Escherichia coli Proteins; Ethylmaleimide; Membrane Transport Proteins; Models, Molecular; Molecular Sequence Data; Monosaccharide Transport Proteins; Mutagenesis, Insertional; Mutagenesis, Site-Directed; Phosphoenolpyruvate Sugar Phosphotransferase System; Protein Conformation; Substrate Specificity; Symporters
PubMed: 9391057
DOI: 10.1073/pnas.94.25.13515 -
World Journal of Microbiology &... Jul 2019Microorganisms have evolved permeases to incorporate various essential nutrients and exclude harmful products, which assists in adaptation to different environmental... (Review)
Review
Microorganisms have evolved permeases to incorporate various essential nutrients and exclude harmful products, which assists in adaptation to different environmental conditions for survival. As permeases are directly involved in the utilization of and regulatory response to nutrient sources, metabolic engineering of microbial permeases can predictably influence nutrient metabolism and regulation. In this mini-review, we have summarized the mechanisms underlying the general regulation of permeases, and the current advancements and future prospects of metabolic engineering strategies targeting the permeases in Saccharomyces cerevisiae. The different types of permeases and their regulatory mechanisms have been discussed. Furthermore, methods for metabolic engineering of permeases have been highlighted. Understanding the mechanisms via which permeases are meticulously regulated and engineered will not only facilitate research on regulation of global nutrition and yeast metabolic engineering, but can also provide important insights for future studies on the synthesis of valuable products and elimination of harmful substances in S. cerevisiae.
Topics: Biological Transport; Carbon; Glucose; Membrane Transport Proteins; Metabolic Engineering; Nitrogen; Saccharomyces cerevisiae
PubMed: 31286266
DOI: 10.1007/s11274-019-2684-z -
Biochemistry Apr 1995As much as 20-30 mg of functional recombinant melibiose permease (Mel-6His permease) of Escherichia coli, carrying a carboxy-terminal affinity tag for metallic ions (six...
As much as 20-30 mg of functional recombinant melibiose permease (Mel-6His permease) of Escherichia coli, carrying a carboxy-terminal affinity tag for metallic ions (six successive histidines), can be routinely purified from 10 g of cells (dry weight) by combining nickel chelate affinity chromatography and ion exchange chromatography. Mel-6His permease was constructed by modifying the permease gene (melB) in vitro and then overproduced in cells transformed with multicopy plasmids. The tagged permease was efficiently solubilized in the presence of 3-(laurylamido)-N,N'-dimethylaminopropylamine oxide (LAPAO) and high sodium salt concentration and then selectively adsorbed on a nickel nitrilotriacetic acid (Ni-NTA) affinity resin. After the replacement of LAPAO by n-dodecyl beta-D-maltoside to maintain the activity of the soluble permease in low ionic strength media, the permease-enriched fraction (> 90%) was eluted with 0.1 M imidazole and finally purified to homogeneity (> 99%) using ion exchange chromatography. Determination of the permease N-terminal sequence shows that an initiating methionine is missing and that a Ser-Ile-Ser stretch precedes the postulated primary amino acid sequence. Purified permeases, reconstituted in liposomes, display H(+)-, Na(+)-, or Li(+)-dependent sugar binding and active transport activities similar to those of the native permease in its natural environment, proving that all three modes of symport activity are mediated by one and the same polypeptide.
Topics: Amino Acid Sequence; Base Sequence; Biological Transport; Carbohydrate Metabolism; Chromatography, Affinity; Chromatography, Ion Exchange; Detergents; Escherichia coli; Gene Deletion; Gene Expression; Gene Transfer Techniques; Liposomes; Lithium; Membrane Transport Proteins; Molecular Sequence Data; Mutagenesis, Site-Directed; Protons; Sodium; Solubility; Structure-Activity Relationship; Symporters
PubMed: 7703254
DOI: 10.1021/bi00013a033 -
Journal of Biochemistry Apr 1992Lactose permease, the lacY gene product in Escherichia coli, is an integral membrane protein. Its induction was examined in secAts and secYts mutants by measuring... (Comparative Study)
Comparative Study
Lactose permease, the lacY gene product in Escherichia coli, is an integral membrane protein. Its induction was examined in secAts and secYts mutants by measuring o-nitrophenyl-beta-galactoside uptake activity. In contrast to the synthesis of the maltose binding protein, the malE gene product, which is dependent on the secA and secY gene products, lactose permease seemed to be produced and integrated functionally into membrane independently of SecA or SecY. Gene fusion of the lamB signal sequence to the N-terminal part of the lactose permease gene resulted in production of active fused permease in the E. coli membrane. The signal sequence did not seem to be processed, judging from its mobility on SDS polyacrylamide gel electrophoresis. E. coli cell growth was super-sensitive to induction of production of the fused permease with the signal sequence in contrast to induction of the normal lactose permease. These results are consistent with the above observation that production and integration of LacY protein into membrane is relatively independent of the SecY protein that may have a certain specificity for the signal sequence or, more generally, membrane translocation intermediates.
Topics: Amino Acid Sequence; Bacterial Outer Membrane Proteins; Bacterial Proteins; Base Sequence; Biological Transport; Cell Division; Cell Membrane; Cloning, Molecular; Enzyme Induction; Escherichia coli; Escherichia coli Proteins; Lactose; Membrane Proteins; Membrane Transport Proteins; Molecular Sequence Data; Monosaccharide Transport Proteins; Mutation; Porins; Protein Sorting Signals; Receptors, Virus; Recombinant Fusion Proteins; Symporters
PubMed: 1618733
DOI: 10.1093/oxfordjournals.jbchem.a123777 -
The Journal of Biological Chemistry Sep 1989The sugar specificity properties of the lactose permease were investigated. Free galactose was shown to competitively inhibit the lactose permease yielding a Ki value of...
The sugar specificity properties of the lactose permease were investigated. Free galactose was shown to competitively inhibit the lactose permease yielding a Ki value of 7.4 mM. This value was severalfold higher than the observed Km for lactose (1.3 mM). A variety of other monosaccharides also showed significant inhibition of lactose transport. With regard to -OH groups along the galactose ring it appears that the relative importance is OH-3 greater than OH-4 greater than OH-6 greater than OH-2 greater than OH-1. In general, galactosides with alpha-linkages exhibited significantly higher affinities compared with their beta-linked counterparts. An optimal size for the aglycone portion of the galactoside was reached with aglycones containing hexose residues or a benzene ring. The preferred size of the aglycone appears to be hexose, benzene ring greater than methyl group greater than no aglycone much greater than disaccharide greater than trisaccharide. However, neither the specific structure of the aglycone nor its relative hydrophobicity appeared to be important factors in permease recognition. For example, the hydrophobic beta-nitrophenyl-galactosides had lower affinities compared with lactose (a beta-galactoside), whereas the alpha-nitrophenylgalactosides generally had higher affinities compared with melibiose (an alpha-galactoside). In addition, no consistent preference was seen when considering the location of the nitro group on the benzene ring. From this work, a model is presented which depicts the binding of galactosides to the lactose permease.
Topics: Binding Sites; Disaccharides; Escherichia coli; Escherichia coli Proteins; Galactose; Glycosides; Kinetics; Lactose; Membrane Transport Modulators; Membrane Transport Proteins; Models, Theoretical; Monosaccharide Transport Proteins; Monosaccharides; Protein Binding; Structure-Activity Relationship; Substrate Specificity; Symporters
PubMed: 2674121
DOI: No ID Found -
Proceedings of the National Academy of... Aug 1987Mutants of lactose permease of Escherichia coli with amino acid changes (Gly-24----Glu; Gly-24----Arg; Pro-28---Ser; Gly-24, Pro-28----Glu-Ser and Gly-24,...
Mutants of lactose permease of Escherichia coli with amino acid changes (Gly-24----Glu; Gly-24----Arg; Pro-28---Ser; Gly-24, Pro-28----Glu-Ser and Gly-24, Pro-28----Arg-Ser) within a putative membrane-spanning alpha-helix (Phe-Gly-Leu-Phe-Phe-Phe-Phe-Tyr-Phe-Phe-Ile-Met-Gly- Ala-Tyr-Phe-Pro-Phe-Phe-Pro-Ile) are incorporated into the cytoplasmic membrane. The mutant proteins retain the ability to bind galactosides, and the affinity for several substrates is actually increased. However, the rate of active transport is decreased to 0.01% of the wild-type rate in the mutants carrying Arg-24 or Arg-24, Ser-28. Kinetic analysis demonstrates that the two mutants require 10 min to cause occupied binding sites for galactoside and H+ to change their exposure from the periplasm to the cytoplasm as compared to 50 ms in the wild type. The effect is less pronounced when these sites are unoccupied.
Topics: Amino Acid Sequence; Biological Transport; DNA, Bacterial; Escherichia coli; Escherichia coli Proteins; Galactosides; Kinetics; Membrane Transport Proteins; Monosaccharide Transport Proteins; Mutation; Symporters; Translocation, Genetic
PubMed: 3303027
DOI: 10.1073/pnas.84.16.5535 -
International Journal of Molecular... Mar 2021Active transport of sugars into bacteria occurs through symporters driven by ion gradients. is the most well-studied proton sugar symporter, whereas is the most... (Review)
Review
Active transport of sugars into bacteria occurs through symporters driven by ion gradients. is the most well-studied proton sugar symporter, whereas is the most characterized sodium sugar symporter. These are members of the major facilitator (MFS) and the amino acid-Polyamine organocation (APS) transporter superfamilies. While there is no structural homology between these transporters, they operate by a similar mechanism. They are nano-machines driven by their respective ion electrochemical potential gradients across the membrane. has 12 transmembrane helices (TMs) organized in two 6-TM bundles, each containing two 3-helix TM repeats. has a core structure of 10 TM helices organized in two inverted repeats (TM 1-5 and TM 6-10). In each case, a single sugar is bound in a central cavity and sugar selectivity is determined by hydrogen- and hydrophobic- bonding with side chains in the binding site. In vSGLT, the sodium-binding site is formed through coordination with carbonyl- and hydroxyl-oxygens from neighboring side chains, whereas in the proton (HO) site is thought to be a single glutamate residue (Glu325). The remaining challenge for both transporters is to determine how ion electrochemical potential gradients drive uphill sugar transport.
Topics: Binding Sites; Biological Transport, Active; Escherichia coli Proteins; Glucose; Lactose; Membrane Transport Proteins; Models, Molecular; Monosaccharide Transport Proteins; Protein Conformation; Sodium-Glucose Transport Proteins; Sugars; Symporters
PubMed: 33808202
DOI: 10.3390/ijms22073572 -
FEMS Microbiology Letters Jun 2016Genes encoding fluoride transporters have been identified in bacterial and archaeal species. The genome sequence of the cariogenic Streptococcus mutans bacteria...
Genes encoding fluoride transporters have been identified in bacterial and archaeal species. The genome sequence of the cariogenic Streptococcus mutans bacteria suggests the presence of a putative fluoride transporter, which is referred to as a chloride channel permease. Two homologues of this gene (GenBank locus tags SMU_1290c and SMU_1289c) reside in tandem in the genome of S. mutans The aim of this study was to determine whether the chloride channel permeases contribute to fluoride resistance. We constructed SMU_1290c- and SMU_1289c-knockout S. mutans UA159 strains. We also constructed a double-knockout strain lacking both genes. SMU_1290c or SMU_1289c was transformed into a fluoride transporter- disrupted Escherichia coli strain. All bacterial strains were cultured under appropriate conditions with or without sodium fluoride, and fluoride resistance was evaluated. All three gene-knockout S. mutans strains showed lower resistance to sodium fluoride than did the wild-type strain. No significant changes in resistance to other sodium halides were recognized between the wild-type and double-knockout strains. Both SMU_1290c and SMU_1289c transformation rescued fluoride transporter-disrupted E. coli cell from fluoride toxicity. We conclude that the chloride channel permeases contribute to fluoride resistance in S. mutans.
Topics: Bacterial Proteins; Chloride Channels; Drug Resistance, Bacterial; Escherichia coli; Gene Knockout Techniques; Genome, Bacterial; Membrane Transport Proteins; Sodium; Sodium Fluoride; Streptococcus mutans
PubMed: 27190286
DOI: 10.1093/femsle/fnw101