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Mechanism of Disruption of the Amt-GlnK Complex by P(II)-Mediated Sensing of 2-Oxoglutarate

GlnK proteins regulate the active uptake of ammonium by Amt transport proteins by inserting their regulatory T-loops into the transport channels of the Amt trimer and physically blocking substrate passage. They sense the cellular nitrogen status through 2-oxoglutarate, and the energy level of the ce...

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Autores principales: Maier, Sarah, Schleberger, Paula, Lü, Wei, Wacker, Tobias, Pflüger, Tobias, Litz, Claudia, Andrade, Susana L. A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3198391/
https://www.ncbi.nlm.nih.gov/pubmed/22039461
http://dx.doi.org/10.1371/journal.pone.0026327
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author Maier, Sarah
Schleberger, Paula
Lü, Wei
Wacker, Tobias
Pflüger, Tobias
Litz, Claudia
Andrade, Susana L. A.
author_facet Maier, Sarah
Schleberger, Paula
Lü, Wei
Wacker, Tobias
Pflüger, Tobias
Litz, Claudia
Andrade, Susana L. A.
author_sort Maier, Sarah
collection PubMed
description GlnK proteins regulate the active uptake of ammonium by Amt transport proteins by inserting their regulatory T-loops into the transport channels of the Amt trimer and physically blocking substrate passage. They sense the cellular nitrogen status through 2-oxoglutarate, and the energy level of the cell by binding both ATP and ADP with different affinities. The hyperthermophilic euryarchaeon Archaeoglobus fulgidus possesses three Amt proteins, each encoded in an operon with a GlnK ortholog. One of these proteins, GlnK2 was recently found to be incapable of binding 2-OG, and in order to understand the implications of this finding we conducted a detailed structural and functional analysis of a second GlnK protein from A. fulgidus, GlnK3. Contrary to Af-GlnK2 this protein was able to bind both ATP/2-OG and ADP to yield inactive and functional states, respectively. Due to the thermostable nature of the protein we could observe the exact positioning of the notoriously flexible T-loops and explain the binding behavior of GlnK proteins to their interaction partner, the Amt proteins. A thermodynamic analysis of these binding events using microcalorimetry evaluated by microstate modeling revealed significant differences in binding cooperativity compared to other characterized P(II) proteins, underlining the diversity and adaptability of this class of regulatory signaling proteins.
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spelling pubmed-31983912011-10-28 Mechanism of Disruption of the Amt-GlnK Complex by P(II)-Mediated Sensing of 2-Oxoglutarate Maier, Sarah Schleberger, Paula Lü, Wei Wacker, Tobias Pflüger, Tobias Litz, Claudia Andrade, Susana L. A. PLoS One Research Article GlnK proteins regulate the active uptake of ammonium by Amt transport proteins by inserting their regulatory T-loops into the transport channels of the Amt trimer and physically blocking substrate passage. They sense the cellular nitrogen status through 2-oxoglutarate, and the energy level of the cell by binding both ATP and ADP with different affinities. The hyperthermophilic euryarchaeon Archaeoglobus fulgidus possesses three Amt proteins, each encoded in an operon with a GlnK ortholog. One of these proteins, GlnK2 was recently found to be incapable of binding 2-OG, and in order to understand the implications of this finding we conducted a detailed structural and functional analysis of a second GlnK protein from A. fulgidus, GlnK3. Contrary to Af-GlnK2 this protein was able to bind both ATP/2-OG and ADP to yield inactive and functional states, respectively. Due to the thermostable nature of the protein we could observe the exact positioning of the notoriously flexible T-loops and explain the binding behavior of GlnK proteins to their interaction partner, the Amt proteins. A thermodynamic analysis of these binding events using microcalorimetry evaluated by microstate modeling revealed significant differences in binding cooperativity compared to other characterized P(II) proteins, underlining the diversity and adaptability of this class of regulatory signaling proteins. Public Library of Science 2011-10-19 /pmc/articles/PMC3198391/ /pubmed/22039461 http://dx.doi.org/10.1371/journal.pone.0026327 Text en Maier et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Maier, Sarah
Schleberger, Paula
Lü, Wei
Wacker, Tobias
Pflüger, Tobias
Litz, Claudia
Andrade, Susana L. A.
Mechanism of Disruption of the Amt-GlnK Complex by P(II)-Mediated Sensing of 2-Oxoglutarate
title Mechanism of Disruption of the Amt-GlnK Complex by P(II)-Mediated Sensing of 2-Oxoglutarate
title_full Mechanism of Disruption of the Amt-GlnK Complex by P(II)-Mediated Sensing of 2-Oxoglutarate
title_fullStr Mechanism of Disruption of the Amt-GlnK Complex by P(II)-Mediated Sensing of 2-Oxoglutarate
title_full_unstemmed Mechanism of Disruption of the Amt-GlnK Complex by P(II)-Mediated Sensing of 2-Oxoglutarate
title_short Mechanism of Disruption of the Amt-GlnK Complex by P(II)-Mediated Sensing of 2-Oxoglutarate
title_sort mechanism of disruption of the amt-glnk complex by p(ii)-mediated sensing of 2-oxoglutarate
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3198391/
https://www.ncbi.nlm.nih.gov/pubmed/22039461
http://dx.doi.org/10.1371/journal.pone.0026327
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