Function Trumps Form in Two Sugar Symporters, LacY and vSGLT †

Active transport of sugars into bacteria occurs through symporters driven by ion gradients. LacY is the most well-studied proton sugar symporter, whereas vSGLT is the most characterized sodium sugar symporter. These are members of the major facilitator (MFS) and the amino acid-Polyamine organocation...

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Autores principales: Abramson, Jeff, Wright, Ernest M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8037263/
https://www.ncbi.nlm.nih.gov/pubmed/33808202
http://dx.doi.org/10.3390/ijms22073572
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author Abramson, Jeff
Wright, Ernest M.
author_facet Abramson, Jeff
Wright, Ernest M.
author_sort Abramson, Jeff
collection PubMed
description Active transport of sugars into bacteria occurs through symporters driven by ion gradients. LacY is the most well-studied proton sugar symporter, whereas vSGLT is the most characterized sodium sugar symporter. These are members of the major facilitator (MFS) and the amino acid-Polyamine organocation (APS) transporter superfamilies. While there is no structural homology between these transporters, they operate by a similar mechanism. They are nano-machines driven by their respective ion electrochemical potential gradients across the membrane. LacY has 12 transmembrane helices (TMs) organized in two 6-TM bundles, each containing two 3-helix TM repeats. vSGLT has a core structure of 10 TM helices organized in two inverted repeats (TM 1–5 and TM 6–10). In each case, a single sugar is bound in a central cavity and sugar selectivity is determined by hydrogen- and hydrophobic- bonding with side chains in the binding site. In vSGLT, the sodium-binding site is formed through coordination with carbonyl- and hydroxyl-oxygens from neighboring side chains, whereas in LacY the proton (H(3)O(+)) site is thought to be a single glutamate residue (Glu325). The remaining challenge for both transporters is to determine how ion electrochemical potential gradients drive uphill sugar transport.
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spelling pubmed-80372632021-04-12 Function Trumps Form in Two Sugar Symporters, LacY and vSGLT † Abramson, Jeff Wright, Ernest M. Int J Mol Sci Review Active transport of sugars into bacteria occurs through symporters driven by ion gradients. LacY is the most well-studied proton sugar symporter, whereas vSGLT is the most characterized sodium sugar symporter. These are members of the major facilitator (MFS) and the amino acid-Polyamine organocation (APS) transporter superfamilies. While there is no structural homology between these transporters, they operate by a similar mechanism. They are nano-machines driven by their respective ion electrochemical potential gradients across the membrane. LacY has 12 transmembrane helices (TMs) organized in two 6-TM bundles, each containing two 3-helix TM repeats. vSGLT has a core structure of 10 TM helices organized in two inverted repeats (TM 1–5 and TM 6–10). In each case, a single sugar is bound in a central cavity and sugar selectivity is determined by hydrogen- and hydrophobic- bonding with side chains in the binding site. In vSGLT, the sodium-binding site is formed through coordination with carbonyl- and hydroxyl-oxygens from neighboring side chains, whereas in LacY the proton (H(3)O(+)) site is thought to be a single glutamate residue (Glu325). The remaining challenge for both transporters is to determine how ion electrochemical potential gradients drive uphill sugar transport. MDPI 2021-03-30 /pmc/articles/PMC8037263/ /pubmed/33808202 http://dx.doi.org/10.3390/ijms22073572 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) ).
spellingShingle Review
Abramson, Jeff
Wright, Ernest M.
Function Trumps Form in Two Sugar Symporters, LacY and vSGLT †
title Function Trumps Form in Two Sugar Symporters, LacY and vSGLT †
title_full Function Trumps Form in Two Sugar Symporters, LacY and vSGLT †
title_fullStr Function Trumps Form in Two Sugar Symporters, LacY and vSGLT †
title_full_unstemmed Function Trumps Form in Two Sugar Symporters, LacY and vSGLT †
title_short Function Trumps Form in Two Sugar Symporters, LacY and vSGLT †
title_sort function trumps form in two sugar symporters, lacy and vsglt †
topic Review
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8037263/
https://www.ncbi.nlm.nih.gov/pubmed/33808202
http://dx.doi.org/10.3390/ijms22073572
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