Polycation-π interactions are a driving force for molecular recognition by an intrinsically disordered oncoprotein family.

Molecular recognition by intrinsically disordered proteins (IDPs) commonly involves specific localized contacts and target-induced disorder to order transitions. However, some IDPs remain disordered in the bound state, a phenomenon coined "fuzziness", often characterized by IDP polyvalency...

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Main Authors: Jianhui Song, Sheung Chun Ng, Peter Tompa, Kevin A W Lee, Hue Sun Chan
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2013-01-01
Series:PLoS Computational Biology
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/24086122/pdf/?tool=EBI
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author Jianhui Song
Sheung Chun Ng
Peter Tompa
Kevin A W Lee
Hue Sun Chan
author_facet Jianhui Song
Sheung Chun Ng
Peter Tompa
Kevin A W Lee
Hue Sun Chan
author_sort Jianhui Song
collection DOAJ
description Molecular recognition by intrinsically disordered proteins (IDPs) commonly involves specific localized contacts and target-induced disorder to order transitions. However, some IDPs remain disordered in the bound state, a phenomenon coined "fuzziness", often characterized by IDP polyvalency, sequence-insensitivity and a dynamic ensemble of disordered bound-state conformations. Besides the above general features, specific biophysical models for fuzzy interactions are mostly lacking. The transcriptional activation domain of the Ewing's Sarcoma oncoprotein family (EAD) is an IDP that exhibits many features of fuzziness, with multiple EAD aromatic side chains driving molecular recognition. Considering the prevalent role of cation-π interactions at various protein-protein interfaces, we hypothesized that EAD-target binding involves polycation- π contacts between a disordered EAD and basic residues on the target. Herein we evaluated the polycation-π hypothesis via functional and theoretical interrogation of EAD variants. The experimental effects of a range of EAD sequence variations, including aromatic number, aromatic density and charge perturbations, all support the cation-π model. Moreover, the activity trends observed are well captured by a coarse-grained EAD chain model and a corresponding analytical model based on interaction between EAD aromatics and surface cations of a generic globular target. EAD-target binding, in the context of pathological Ewing's Sarcoma oncoproteins, is thus seen to be driven by a balance between EAD conformational entropy and favorable EAD-target cation-π contacts. Such a highly versatile mode of molecular recognition offers a general conceptual framework for promiscuous target recognition by polyvalent IDPs.
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spelling doaj.art-ec57d0a2b316409cb04e42cf4687e3762022-12-21T21:43:35ZengPublic Library of Science (PLoS)PLoS Computational Biology1553-734X1553-73582013-01-0199e100323910.1371/journal.pcbi.1003239Polycation-π interactions are a driving force for molecular recognition by an intrinsically disordered oncoprotein family.Jianhui SongSheung Chun NgPeter TompaKevin A W LeeHue Sun ChanMolecular recognition by intrinsically disordered proteins (IDPs) commonly involves specific localized contacts and target-induced disorder to order transitions. However, some IDPs remain disordered in the bound state, a phenomenon coined "fuzziness", often characterized by IDP polyvalency, sequence-insensitivity and a dynamic ensemble of disordered bound-state conformations. Besides the above general features, specific biophysical models for fuzzy interactions are mostly lacking. The transcriptional activation domain of the Ewing's Sarcoma oncoprotein family (EAD) is an IDP that exhibits many features of fuzziness, with multiple EAD aromatic side chains driving molecular recognition. Considering the prevalent role of cation-π interactions at various protein-protein interfaces, we hypothesized that EAD-target binding involves polycation- π contacts between a disordered EAD and basic residues on the target. Herein we evaluated the polycation-π hypothesis via functional and theoretical interrogation of EAD variants. The experimental effects of a range of EAD sequence variations, including aromatic number, aromatic density and charge perturbations, all support the cation-π model. Moreover, the activity trends observed are well captured by a coarse-grained EAD chain model and a corresponding analytical model based on interaction between EAD aromatics and surface cations of a generic globular target. EAD-target binding, in the context of pathological Ewing's Sarcoma oncoproteins, is thus seen to be driven by a balance between EAD conformational entropy and favorable EAD-target cation-π contacts. Such a highly versatile mode of molecular recognition offers a general conceptual framework for promiscuous target recognition by polyvalent IDPs.https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/24086122/pdf/?tool=EBI
spellingShingle Jianhui Song
Sheung Chun Ng
Peter Tompa
Kevin A W Lee
Hue Sun Chan
Polycation-π interactions are a driving force for molecular recognition by an intrinsically disordered oncoprotein family.
PLoS Computational Biology
title Polycation-π interactions are a driving force for molecular recognition by an intrinsically disordered oncoprotein family.
title_full Polycation-π interactions are a driving force for molecular recognition by an intrinsically disordered oncoprotein family.
title_fullStr Polycation-π interactions are a driving force for molecular recognition by an intrinsically disordered oncoprotein family.
title_full_unstemmed Polycation-π interactions are a driving force for molecular recognition by an intrinsically disordered oncoprotein family.
title_short Polycation-π interactions are a driving force for molecular recognition by an intrinsically disordered oncoprotein family.
title_sort polycation π interactions are a driving force for molecular recognition by an intrinsically disordered oncoprotein family
url https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/24086122/pdf/?tool=EBI
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