Critical role of a conserved transmembrane lysine in substrate recognition by the proton-coupled oligopeptide transporter YjdL

Proton-coupled oligopeptide transporters (POTs) utilize an electrochemical proton gradient to accumulate peptides in the cytoplasm. Changing the highly conserved active-site Lys117 in the Escherichia coli POT YjdL to glutamine resulted in loss of ligand affinity as well as inability to distinguish b...

Full description

Saved in:
Bibliographic Details
Published in:The international journal of biochemistry & cell biology 2014-10, Vol.55, p.311-317
Main Authors: Jensen, Johanne M., Aduri, Nanda G., Prabhala, Bala K., Jahnsen, Rasmus, Franzyk, Henrik, Mirza, Osman
Format: Article
Language:English
Subjects:
Affinity
Amino Acid Motifs - genetics
Amino Acid Sequence
Binding Sites - genetics
Biochemistry
Biological Transport - genetics
Biology
Cell Membrane - metabolism
Conserved Sequence - genetics
Escherichia coli
Escherichia coli Proteins - chemistry
Escherichia coli Proteins - genetics
Escherichia coli Proteins - metabolism
Glutamine - chemistry
Glutamine - genetics
Glutamine - metabolism
Kinetics
Ligands
Lysine
Lysine - chemistry
Lysine - genetics
Lysine - metabolism
Membrane Transport Proteins - chemistry
Membrane Transport Proteins - genetics
Membrane Transport Proteins - metabolism
Models, Molecular
Molecular Sequence Data
Mutation, Missense
Oligopeptides - chemistry
Oligopeptides - metabolism
Peptide binding
Peptides
pH profiles
POTs
Protein Binding
Protein Structure, Tertiary
Proton coupling
Protons
Sequence Homology, Amino Acid
Substrate Specificity
Transporter
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Proton-coupled oligopeptide transporters (POTs) utilize an electrochemical proton gradient to accumulate peptides in the cytoplasm. Changing the highly conserved active-site Lys117 in the Escherichia coli POT YjdL to glutamine resulted in loss of ligand affinity as well as inability to distinguish between a dipeptide ligand and the corresponding dipeptide amide. The radically changed pHBulk profiles of Lys117Gln and Lys117Arg mutants indicate an important role of Lys117 in facilitating protonation of the transporter; a notion that is supported by the close proximity of Lys117 to the conserved ExxERFxYY POT motif previously shown to be involved in proton translocation. These results point toward a novel dual role of Lys117 in direct or indirect interaction with both proton and peptide.
ISSN:1357-2725
1878-5875
DOI:10.1016/j.biocel.2014.09.016