Role of Ser-340 and Thr-341 in transmembrane domain IX of the Na+/Proline transporter PutP of Escherichia coli in ligand binding and transport

DC FieldValueLanguage
dc.contributor.authorHilger, Daniel
dc.contributor.authorBohm, Maret
dc.contributor.authorHackmann, Alexandra
dc.contributor.authorJung, Heinrich
dc.date.accessioned2021-12-23T16:13:59Z-
dc.date.available2021-12-23T16:13:59Z-
dc.date.issued2008
dc.identifier.urihttps://osnascholar.ub.uni-osnabrueck.de/handle/unios/10847-
dc.description.abstractThe Na+/solute symporter family comprises more than 400 members of pro- and eukaryotic origin. Using the Na+/proline transporter PutP of Escherichia coli as a model, the role of two conserved residues, Ser-340 and Thr-341, is investigated to obtain insights into the mechanism of transport catalyzed by members of this family. Substitution of these amino acids alters the transport kinetics of cells and proteoliposomes containing the PutP variants significantly. In particular, the apparent affinities for Na+ and Li+ are reduced by 2 orders of magnitude or more. Also proline binding is affected, albeit to a lesser extent than ion binding. Thereby, the presence of a hydroxyl group at position 341 is essential for high affinity ligand binding. Furthermore, Cys placed at position 340 or 341 reacts with sulfhydryl reagents of different polarity, indicating accessibility from the water phase. In addition, Cys cross-linking suggests proximity of the residues to other amino acids previously shown to be crucial for ligand binding. For these reasons it is suggested that Ser-340 and Thr-341 are located in a ligand translocation pathway. Furthermore, it is proposed that the side chain of Thr-341 directly participates in Na+ binding.
dc.language.isoen
dc.publisherAMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
dc.relation.ispartofJOURNAL OF BIOLOGICAL CHEMISTRY
dc.subjectBiochemistry & Molecular Biology
dc.subjectMEMBRANE
dc.subjectNA+
dc.subjectNA+/GLUCOSE COTRANSPORTER
dc.subjectPERMEASE
dc.subjectPROLINE UPTAKE
dc.subjectPROTEIN
dc.subjectRECONSTITUTION
dc.subjectSUGAR-BINDING
dc.subjectSYMPORTER FAMILY
dc.subjectTOPOLOGY
dc.titleRole of Ser-340 and Thr-341 in transmembrane domain IX of the Na+/Proline transporter PutP of Escherichia coli in ligand binding and transport
dc.typejournal article
dc.identifier.doi10.1074/jbc.M706741200
dc.identifier.isiISI:000253426500050
dc.description.volume283
dc.description.issue8
dc.description.startpage4921
dc.description.endpage4929
dc.contributor.orcid0000-0001-5179-1357
dc.contributor.orcid0000-0002-5450-3063
dc.contributor.researcheridC-7297-2019
dc.contributor.researcheridK-3790-2014
dc.identifier.eissn1083351X
dc.publisher.place9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA
dcterms.isPartOf.abbreviationJ. Biol. Chem.
dcterms.oaStatushybrid
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