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

TY - JOUR

T1 - Critical role of a conserved transmembrane lysine in substrate recognition by the proton-coupled oligopeptide transporter YjdL

AU - Jensen, Johanne M

AU - Aduri, Nanda Gowtham

AU - Prabhala, Bala K

AU - Jahnsen, Rasmus

AU - Franzyk, Henrik

AU - Mirza, Osman Asghar

N1 - Copyright © 2014. Published by Elsevier Ltd.

PY - 2014/10

Y1 - 2014/10

N2 - 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.

AB - 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.

U2 - 10.1016/j.biocel.2014.09.016

DO - 10.1016/j.biocel.2014.09.016

M3 - Journal article

C2 - 25261786

SN - 1357-2725

VL - 55

SP - 311

EP - 317

JO - International Journal of Biochemistry & Cell Biology

JF - International Journal of Biochemistry & Cell Biology

ER -