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Structural Dynamics Control Allosteric Activation of Cytohesin Family Arf GTPase Exchange Factors

Membrane dynamic processes including vesicle biogenesis depend on Arf GTPase activation by guanine nucleotide exchange factors (GEFs) containing a catalytic Sec7 domain and a membrane targeting module such as a PH domain. The catalytic output of cytohesin family Arf GEFs is controlled by autoinhibit...

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Autores principales: Malaby, Andrew W., Das, Sanchaita, Chakravarthy, Srinivas, Irving, Thomas C., Bilsel, Osman, Lambright, David G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5752578/
https://www.ncbi.nlm.nih.gov/pubmed/29276036
http://dx.doi.org/10.1016/j.str.2017.11.019
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author Malaby, Andrew W.
Das, Sanchaita
Chakravarthy, Srinivas
Irving, Thomas C.
Bilsel, Osman
Lambright, David G.
author_facet Malaby, Andrew W.
Das, Sanchaita
Chakravarthy, Srinivas
Irving, Thomas C.
Bilsel, Osman
Lambright, David G.
author_sort Malaby, Andrew W.
collection PubMed
description Membrane dynamic processes including vesicle biogenesis depend on Arf GTPase activation by guanine nucleotide exchange factors (GEFs) containing a catalytic Sec7 domain and a membrane targeting module such as a PH domain. The catalytic output of cytohesin family Arf GEFs is controlled by autoinhibitory interactions that impede accessibility of the exchange site in the Sec7 domain. These restraints can be relieved through activator Arf-GTP binding to an allosteric site comprising the PH domain and proximal autoinhibitory elements (Sec7-PH linker and C-terminal helix). Small angle X-ray scattering and negative-stain electron microscopy were used to investigate the structural organization and conformational dynamics of Cytohesin-3 (Grp1) in autoinhibited and active states. The results support a model in which hinge dynamics in the autoinhibited state expose the activator site for Arf-GTP binding, while subsequent C-terminal helix unlatching and repositioning unleash conformational entropy in the Sec7-PH linker to drive exposure of the exchange site.
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spelling pubmed-57525782019-01-02 Structural Dynamics Control Allosteric Activation of Cytohesin Family Arf GTPase Exchange Factors Malaby, Andrew W. Das, Sanchaita Chakravarthy, Srinivas Irving, Thomas C. Bilsel, Osman Lambright, David G. Structure Article Membrane dynamic processes including vesicle biogenesis depend on Arf GTPase activation by guanine nucleotide exchange factors (GEFs) containing a catalytic Sec7 domain and a membrane targeting module such as a PH domain. The catalytic output of cytohesin family Arf GEFs is controlled by autoinhibitory interactions that impede accessibility of the exchange site in the Sec7 domain. These restraints can be relieved through activator Arf-GTP binding to an allosteric site comprising the PH domain and proximal autoinhibitory elements (Sec7-PH linker and C-terminal helix). Small angle X-ray scattering and negative-stain electron microscopy were used to investigate the structural organization and conformational dynamics of Cytohesin-3 (Grp1) in autoinhibited and active states. The results support a model in which hinge dynamics in the autoinhibited state expose the activator site for Arf-GTP binding, while subsequent C-terminal helix unlatching and repositioning unleash conformational entropy in the Sec7-PH linker to drive exposure of the exchange site. 2017-12-21 2018-01-02 /pmc/articles/PMC5752578/ /pubmed/29276036 http://dx.doi.org/10.1016/j.str.2017.11.019 Text en http://creativecommons.org/licenses/by-nc-nd/4.0/ This manuscript version is made available under the CC BY-NC-ND 4.0 license.
spellingShingle Article
Malaby, Andrew W.
Das, Sanchaita
Chakravarthy, Srinivas
Irving, Thomas C.
Bilsel, Osman
Lambright, David G.
Structural Dynamics Control Allosteric Activation of Cytohesin Family Arf GTPase Exchange Factors
title Structural Dynamics Control Allosteric Activation of Cytohesin Family Arf GTPase Exchange Factors
title_full Structural Dynamics Control Allosteric Activation of Cytohesin Family Arf GTPase Exchange Factors
title_fullStr Structural Dynamics Control Allosteric Activation of Cytohesin Family Arf GTPase Exchange Factors
title_full_unstemmed Structural Dynamics Control Allosteric Activation of Cytohesin Family Arf GTPase Exchange Factors
title_short Structural Dynamics Control Allosteric Activation of Cytohesin Family Arf GTPase Exchange Factors
title_sort structural dynamics control allosteric activation of cytohesin family arf gtpase exchange factors
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5752578/
https://www.ncbi.nlm.nih.gov/pubmed/29276036
http://dx.doi.org/10.1016/j.str.2017.11.019
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