The melibiose carrier of Escherichia coli

Botfield, Martyn C.; Wilson, Dorothy M.; Wilson, Thomas H.

doi:10.1016/0923-2508(90)90006-c

Cited by 35 publications

(30 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar to LacY, the melibiose permease MelB is an ion (Na ϩ /H ϩ ) sugar symporter with 12 membrane-spanning segments (74,586,966). S. enterica serovar Typhimurium melB mutants synthesizing an inducer exclusion-resistant melibiose permease have been isolated (439) ( Table 2).…”

Section: Inhibits Transcription Induction Mechanismmentioning

confidence: 99%

How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria

Deutscher

Francke

Postma

2006

Microbiol Mol Biol Rev

1,204

769

View full text Add to dashboard Cite

SUMMARY The phosphoenolpyruvate(PEP):carbohydrate phosphotransferase system (PTS) is found only in bacteria, where it catalyzes the transport and phosphorylation of numerous monosaccharides, disaccharides, amino sugars, polyols, and other sugar derivatives. To carry out its catalytic function in sugar transport and phosphorylation, the PTS uses PEP as an energy source and phosphoryl donor. The phosphoryl group of PEP is usually transferred via four distinct proteins (domains) to the transported sugar bound to the respective membrane component(s) (EIIC and EIID) of the PTS. The organization of the PTS as a four-step phosphoryl transfer system, in which all P derivatives exhibit similar energy (phosphorylation occurs at histidyl or cysteyl residues), is surprising, as a single protein (or domain) coupling energy transfer and sugar phosphorylation would be sufficient for PTS function. A possible explanation for the complexity of the PTS was provided by the discovery that the PTS also carries out numerous regulatory functions. Depending on their phosphorylation state, the four proteins (domains) forming the PTS phosphorylation cascade (EI, HPr, EIIA, and EIIB) can phosphorylate or interact with numerous non-PTS proteins and thereby regulate their activity. In addition, in certain bacteria, one of the PTS components (HPr) is phosphorylated by ATP at a seryl residue, which increases the complexity of PTS-mediated regulation. In this review, we try to summarize the known protein phosphorylation-related regulatory functions of the PTS. As we shall see, the PTS regulation network not only controls carbohydrate uptake and metabolism but also interferes with the utilization of nitrogen and phosphorus and the virulence of certain pathogens.

show abstract

Section: Inhibits Transcription Induction Mechanismmentioning

confidence: 99%

How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria

Deutscher

Francke

Postma

2006

Microbiol Mol Biol Rev

1,204

769

View full text Add to dashboard Cite

show abstract

“…The numbers of amino acid residues are similar in the two transport proteins. Both proteins contain 12 hydrophobic domains which are transmembrane regions (3,5,17). In contrast to these similarities, there is no significant sequence similarity between the two transporters (4,25).…”

mentioning

confidence: 89%

A melibiose transporter and an operon containing its gene in Enterobacter cloacae

et al. 1997

View full text Add to dashboard Cite

We detected inducible melibiose transport activity in cells of Enterobacter cloacae IID977. H ؉ , but not Na ؉ , was found to be the coupling cation for this transporter. We cloned and sequenced the gene encoding the melibiose transporter. A homology search of a protein sequence database revealed that this melibiose transporter has high sequence similarity with the lactose transporter (LacY) and the raffinose transporter (RafB) and has some similarity with the melibiose transporter (MelB) of Escherichia coli.The melibiose transporter (MelB) and the lactose transporter (LacY) of Escherichia coli are secondary membrane transporters which mediate symport of galactosides and monovalent cations. These transporters have been revealed to be valuable systems for elucidation of structure-function relationships in cation-coupled symporters.

show abstract

“…It is not uncommon for cation preference to vary within a single transporter family (Reizer et al, 1994), e.g. the melibiose transporter (MelB) of E. coli mediates uphill transport of melibiose coupled to Na + or H + (Botfield et al, 1990), while that of Klebsiella pneumoniae couples sugar transport to H + and Li + (Hama et al, 1992). Similarly, mammalian SGLT1 and SGLT3 can utilize H + or Li + in addition to Na + as the driving force for sugar transport, whereas SGLT2 is Na + -specific (Wright, 2001).…”

mentioning

confidence: 99%

Functional characterization of a H⁺/nucleoside co‐transporter (CaCNT) from Candida albicans, a fungal member of the concentrative nucleoside transporter (CNT) family of membrane proteins

Loewen

Mohabir

et al. 2003

Yeast

View full text Add to dashboard Cite

Human and other mammalian concentrative (Na + -linked) nucleoside transport proteins belong to a membrane protein family (CNT, TC 2.A.41) that also includes Escherichia coli H + -dependent nucleoside transport protein NupC. Here, we report the cDNA cloning and functional characterization of a CNT family member from the pathogenic yeast Candida albicans. This 608 amino acid residue H + /nucleoside symporter, designated CaCNT, contains 13 predicted transmembrane domains (TMs), but lacks the exofacial, glycosylated carboxyl-terminus of its mammalian counterparts. When produced in Xenopus oocytes, CaCNT exhibited transport activity for adenosine, uridine, inosine and guanosine but not cytidine, thymidine or the nucleobase hypoxanthine. Apparent K m values were in the range 16-64 µM, with V max : K m ratios of 0.58-1.31. CaCNT also accepted purine and uridine analogue nucleoside drugs as permeants, including cordycepin (3 -deoxyadenosine), a nucleoside analogue with anti-fungal activity. Electrophysiological measurements under voltage clamp conditions gave a H + to [ 14 C]uridine coupling ratio of 1 : 1. CaCNT, obtained from logarithmically growing cells, is the first described cationcoupled nucleoside transporter in yeast, and the first member of the CNT family of proteins to be characterized from a unicellular eukaryotic organism.

show abstract

The melibiose carrier of Escherichia coli

Cited by 35 publications

References 8 publications

How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria

How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria

A melibiose transporter and an operon containing its gene in Enterobacter cloacae

Functional characterization of a H⁺/nucleoside co‐transporter (CaCNT) from Candida albicans, a fungal member of the concentrative nucleoside transporter (CNT) family of membrane proteins

Contact Info

Product

Resources

About

The melibiose carrier of Escherichia coli

Cited by 35 publications

References 8 publications

How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria

How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria

A melibiose transporter and an operon containing its gene in Enterobacter cloacae

Functional characterization of a H+/nucleoside co‐transporter (CaCNT) from Candida albicans, a fungal member of the concentrative nucleoside transporter (CNT) family of membrane proteins

Contact Info

Product

Resources

About

Functional characterization of a H⁺/nucleoside co‐transporter (CaCNT) from Candida albicans, a fungal member of the concentrative nucleoside transporter (CNT) family of membrane proteins