TY - JOUR
T1 - Structure and mechanism of a Na+-independent amino acid transporter
AU - Shaffer, Paul L.
AU - Goehring, April
AU - Shankaranarayanan, Aruna
AU - Gouaux, Eric
N1 - Copyright:
Copyright 2009 Elsevier B.V., All rights reserved.
PY - 2009
Y1 - 2009
N2 - Amino acid, polyamine, and organocation (APC) transporters are secondary transporters that play essential roles in nutrient uptake, neurotransmitter recycling, ionic homeostasis, and regulation of cell volume. Here, we present the crystal structure of apo-ApcT, a proton-coupled broad-specificity amino acid transporter, at 2.35 angstrom resolution. The structure contains 12 transmembrane helices, with the first 10 consisting of an inverted structural repeat of 5 transmembrane helices like the leucine transporter LeuT. The ApcT structure reveals an inward-facing, apo state and an amine moiety of lysine-158 located in a position equivalent to the sodium ion site Na2 of LeuT. We propose that lysine-158 is central to proton-coupled transport and that the amine group serves the same functional role as the Na2 ion in LeuT, thus demonstrating common principles among proton- and sodium-coupled transporters.
AB - Amino acid, polyamine, and organocation (APC) transporters are secondary transporters that play essential roles in nutrient uptake, neurotransmitter recycling, ionic homeostasis, and regulation of cell volume. Here, we present the crystal structure of apo-ApcT, a proton-coupled broad-specificity amino acid transporter, at 2.35 angstrom resolution. The structure contains 12 transmembrane helices, with the first 10 consisting of an inverted structural repeat of 5 transmembrane helices like the leucine transporter LeuT. The ApcT structure reveals an inward-facing, apo state and an amine moiety of lysine-158 located in a position equivalent to the sodium ion site Na2 of LeuT. We propose that lysine-158 is central to proton-coupled transport and that the amine group serves the same functional role as the Na2 ion in LeuT, thus demonstrating common principles among proton- and sodium-coupled transporters.
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U2 - 10.1126/science.1176088
DO - 10.1126/science.1176088
M3 - Article
C2 - 19608859
AN - SCOPUS:69249116947
SN - 0036-8075
VL - 325
SP - 1010
EP - 1014
JO - Science
JF - Science
IS - 5943
ER -