Please use this identifier to cite or link to this item: https://olympias.lib.uoi.gr/jspui/handle/123456789/22638
Full metadata record
DC FieldValueLanguage
dc.contributor.authorFrillingos, S.en
dc.contributor.authorSahin-Toth, M.en
dc.contributor.authorPersson, B.en
dc.contributor.authorKaback, H. R.en
dc.date.accessioned2015-11-24T19:25:35Z-
dc.date.available2015-11-24T19:25:35Z-
dc.identifier.issn0006-2960-
dc.identifier.urihttps://olympias.lib.uoi.gr/jspui/handle/123456789/22638-
dc.rightsDefault Licence-
dc.subjectAmino Acid Sequenceen
dc.subjectBase Sequenceen
dc.subjectCysteine/*geneticsen
dc.subjectEscherichia coli/*genetics/metabolismen
dc.subject*Escherichia coli Proteinsen
dc.subjectLactose/*metabolismen
dc.subjectMembrane Transport Proteins/*genetics/*metabolismen
dc.subjectMolecular Sequence Dataen
dc.subject*Monosaccharide Transport Proteinsen
dc.subjectMutagenesis, Site-Directeden
dc.subjectProtein Structure, Secondaryen
dc.subjectSequence Analysis, DNAen
dc.subjectSequence Homology, Amino Aciden
dc.subjectStructure-Activity Relationshipen
dc.subject*Symportersen
dc.titleCysteine-scanning mutagenesis of putative helix VII in the lactose permease of Escherichia colien
heal.typejournalArticle-
heal.type.enJournal articleen
heal.type.elΆρθρο Περιοδικούel
heal.identifier.secondaryhttp://www.ncbi.nlm.nih.gov/pubmed/8025113-
heal.identifier.secondaryhttp://pubs.acs.org/doi/pdf/10.1021/bi00192a012-
heal.languageen-
heal.accesscampus-
heal.recordProviderΠανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών Υγείας. Τμήμα Ιατρικήςel
heal.publicationDate1994-
heal.abstractUsing a functional lactose permease mutant devoid of Cys residues (C-less permease), each amino acid residue in putative transmembrane helix VII and the flanking cytoplasmic and periplasmic regions (from Leu212 to Glu255) was replaced individually with Cys. Of the 44 single-Cys mutants, 40 exhibit high transport activity, accumulating lactose to > 50% of the steady-state observed with C-less permease. In contrast, permease with Cys in place of Ala213 or Tyr236 exhibits low but significant activity, and Cys substitution for Asp237 or Asp240 yields permease molecules with little or no activity due to disruption of charge-neutralizing interactions between Asp237 and Lys358 or Asp240 and Lys319, respectively. Immunological analysis reveals that membrane levels of the mutant proteins are comparable to that of C-less permease with the exception of Tyr228-->Cys, which exhibits reduced but significant levels of permease. Finally, the effect of N-ethylmaleimide (NEM) was tested on each mutant, and the results indicate that the transport activity of the great majority of the mutants is not affected by the alkylating agent. Remarkably, the six positions where Cys replacements render the permease highly sensitive to inactivation by NEM are confined to the C-terminal half of helix VII, a region that is strongly conserved among transport proteins homologous to lactose permease. The results demonstrate that although no residue per se in the region scanned is essential, structural features of the C terminus of helix VII may be important for transport activity.en
heal.journalNameBiochemistryen
heal.journalTypepeer-reviewed-
heal.fullTextAvailabilityTRUE-
Appears in Collections:Άρθρα σε επιστημονικά περιοδικά ( Ανοικτά) - ΙΑΤ

Files in This Item:
File Description SizeFormat 
Frillingos-1994-Cysteine-scanning mu.pdf3.28 MBAdobe PDFView/Open    Request a copy


This item is licensed under a Creative Commons License Creative Commons