title: The yicM (nepI) gene of Escherichia coli encodes a major facilitator superfamily protein involved in efflux of purine ribonucleosides.
abstract: The yicM gene of Escherichia coli was found by selection for resistance to 6-mercaptopurine. Translation and transcription initiation sites of yicM were determined. Overexpression of yicM increased resistance of sensitive cells to inosine and guanosine, decreased E. coli growth rate in medium containing these ribonucleosides as the sole carbon source, led to inosine accumulation by the E. coli strain deficient in purine nucleoside phosphorylase and enhanced the rate of inosine excretion by an inosine-producing strain. These results suggest that yicM encodes a purine ribonucleoside exporter and we have accordingly renamed it nepI (for 'nucleoside efflux permease-inosine').
authors.affiliation: Ajinomoto-Genetika Research Institute, 1-st Dorozhny Proezd, b.1, Moscow 117545, Russia.
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Gronskiy
authors.forename: Natalia P
authors.initials: NP
authors.lastname: Zakataeva
authors.forename: Maria V
authors.initials: MV
authors.lastname: Vitushkina
authors.forename: Leonid R
authors.initials: LR
authors.lastname: Ptitsyn
authors.forename: Irina B
authors.initials: IB
authors.lastname: Altman
authors.forename: Anna E
authors.initials: AE
authors.lastname: Novikova
authors.forename: Vitaliy A
authors.initials: VA
authors.lastname: Livshits
mesh_terms: D001483:Base Sequence; D001693:Biological Transport, Active; D003001:Cloning, Molecular; D003470:Culture Media; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D005798:Genes, Bacterial; D007288:Inosine / Q000378:metabolism; D015122:Mercaptopurine / Q000494:pharmacology; D008969:Molecular Sequence Data; D033704:Nucleotide Transport Proteins / Q000235:genetics* / Q000378:metabolism*; D014176:Protein Biosynthesis; D011684:Purine Nucleosides / Q000378:metabolism* / Q000494:pharmacology; D011683:Purine-Nucleoside Phosphorylase / Q000378:metabolism; D012263:Ribonucleosides / Q000378:metabolism* / Q000494:pharmacology; D014158:Transcription, Genetic
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D033704:Nucleotide Transport Proteins; D011684:Purine Nucleosides; D012263:Ribonucleosides; D007288:Inosine; D015122:Mercaptopurine; D011683:Purine-Nucleoside Phosphorylase