Structural Study of a Flexible Active Site Loop in Human Indoleamine 2,3-Dioxygenase and Its Functional Implications

Human indoleamine 2,3-dioxygenase catalyzes the oxidative cleavage of tryptophan to N-formyl kynurenine, the initial and rate-limiting step in the kynurenine pathway. Additionally, this enzyme has been identified as a possible target for cancer therapy. A 20-amino acid protein segment (the JK loop),...

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Autores principales: Álvarez, L., Lewis-Ballester, A., Roitberg, A., Estrin, D.A., Yeh, S.-R., Marti, M.A., Capece, L.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00062960_v55_n19_p2785_Alvarez
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spelling todo:paper_00062960_v55_n19_p2785_Alvarez2023-10-03T14:04:36Z Structural Study of a Flexible Active Site Loop in Human Indoleamine 2,3-Dioxygenase and Its Functional Implications Álvarez, L. Lewis-Ballester, A. Roitberg, A. Estrin, D.A. Yeh, S.-R. Marti, M.A. Capece, L. Amino acids Binding energy Bins Catalysis Conformations Enzyme activity Hydrogen bonds Molecular dynamics Mutagenesis Proteins Hydrogen bonding interactions Indoleamine 2 ,3-dioxygenase Post-translational modifications Protein-protein interactions Replica-exchange molecular dynamics simulations Site directed mutagenesis Structural rearrangement Structure and dynamics Crystal structure indoleamine 2,3 dioxygenase kynurenine tryptophan indoleamine 2,3 dioxygenase indoleamine 2,3-dioxygenase 1, human Article binding site cancer therapy catalyst comparative study conformational transition crystal structure enzyme activity enzyme structure human hydrogen bond molecular dynamics priority journal protein protein interaction protein purification protein secondary structure signal transduction site directed mutagenesis static electricity catalysis chemistry genetics metabolism protein domain protein motif structure activity relation X ray crystallography Amino Acid Motifs Catalysis Crystallography, X-Ray Humans Indoleamine-Pyrrole 2,3,-Dioxygenase Mutagenesis, Site-Directed Protein Domains Structure-Activity Relationship Human indoleamine 2,3-dioxygenase catalyzes the oxidative cleavage of tryptophan to N-formyl kynurenine, the initial and rate-limiting step in the kynurenine pathway. Additionally, this enzyme has been identified as a possible target for cancer therapy. A 20-amino acid protein segment (the JK loop), which connects the J and K helices, was not resolved in the reported hIDO crystal structure. Previous studies have shown that this loop undergoes structural rearrangement upon substrate binding. In this work, we apply a combination of replica exchange molecular dynamics simulations and site-directed mutagenesis experiments to characterize the structure and dynamics of this protein region. Our simulations show that the JK loop can be divided into two regions: the first region (JK loopC) displays specific and well-defined conformations and is within hydrogen bonding distance of the substrate, while the second region (JK loopN) is highly disordered and exposed to the solvent. The peculiar flexible nature of JK loopN suggests that it may function as a target for post-translational modifications and/or a mediator for protein-protein interactions. In contrast, hydrogen bonding interactions are observed between the substrate and Thr379 in the highly conserved "GTGG" motif of JK loopC, thereby anchoring JK loopC in a closed conformation, which secures the appropriate substrate binding mode for catalysis. Site-directed mutagenesis experiments confirm the key role of this residue, highlighting the importance of the JK loopC conformation in regulating the enzymatic activity. Furthermore, the existence of the partially and totally open conformations in the substrate-free form suggests a role of JK loopC in controlling substrate and product dynamics. © 2016 American Chemical Society. Fil:Estrin, D.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Marti, M.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Capece, L. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00062960_v55_n19_p2785_Alvarez
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Amino acids
Binding energy
Bins
Catalysis
Conformations
Enzyme activity
Hydrogen bonds
Molecular dynamics
Mutagenesis
Proteins
Hydrogen bonding interactions
Indoleamine 2 ,3-dioxygenase
Post-translational modifications
Protein-protein interactions
Replica-exchange molecular dynamics simulations
Site directed mutagenesis
Structural rearrangement
Structure and dynamics
Crystal structure
indoleamine 2,3 dioxygenase
kynurenine
tryptophan
indoleamine 2,3 dioxygenase
indoleamine 2,3-dioxygenase 1, human
Article
binding site
cancer therapy
catalyst
comparative study
conformational transition
crystal structure
enzyme activity
enzyme structure
human
hydrogen bond
molecular dynamics
priority journal
protein protein interaction
protein purification
protein secondary structure
signal transduction
site directed mutagenesis
static electricity
catalysis
chemistry
genetics
metabolism
protein domain
protein motif
structure activity relation
X ray crystallography
Amino Acid Motifs
Catalysis
Crystallography, X-Ray
Humans
Indoleamine-Pyrrole 2,3,-Dioxygenase
Mutagenesis, Site-Directed
Protein Domains
Structure-Activity Relationship
spellingShingle Amino acids
Binding energy
Bins
Catalysis
Conformations
Enzyme activity
Hydrogen bonds
Molecular dynamics
Mutagenesis
Proteins
Hydrogen bonding interactions
Indoleamine 2 ,3-dioxygenase
Post-translational modifications
Protein-protein interactions
Replica-exchange molecular dynamics simulations
Site directed mutagenesis
Structural rearrangement
Structure and dynamics
Crystal structure
indoleamine 2,3 dioxygenase
kynurenine
tryptophan
indoleamine 2,3 dioxygenase
indoleamine 2,3-dioxygenase 1, human
Article
binding site
cancer therapy
catalyst
comparative study
conformational transition
crystal structure
enzyme activity
enzyme structure
human
hydrogen bond
molecular dynamics
priority journal
protein protein interaction
protein purification
protein secondary structure
signal transduction
site directed mutagenesis
static electricity
catalysis
chemistry
genetics
metabolism
protein domain
protein motif
structure activity relation
X ray crystallography
Amino Acid Motifs
Catalysis
Crystallography, X-Ray
Humans
Indoleamine-Pyrrole 2,3,-Dioxygenase
Mutagenesis, Site-Directed
Protein Domains
Structure-Activity Relationship
Álvarez, L.
Lewis-Ballester, A.
Roitberg, A.
Estrin, D.A.
Yeh, S.-R.
Marti, M.A.
Capece, L.
Structural Study of a Flexible Active Site Loop in Human Indoleamine 2,3-Dioxygenase and Its Functional Implications
topic_facet Amino acids
Binding energy
Bins
Catalysis
Conformations
Enzyme activity
Hydrogen bonds
Molecular dynamics
Mutagenesis
Proteins
Hydrogen bonding interactions
Indoleamine 2 ,3-dioxygenase
Post-translational modifications
Protein-protein interactions
Replica-exchange molecular dynamics simulations
Site directed mutagenesis
Structural rearrangement
Structure and dynamics
Crystal structure
indoleamine 2,3 dioxygenase
kynurenine
tryptophan
indoleamine 2,3 dioxygenase
indoleamine 2,3-dioxygenase 1, human
Article
binding site
cancer therapy
catalyst
comparative study
conformational transition
crystal structure
enzyme activity
enzyme structure
human
hydrogen bond
molecular dynamics
priority journal
protein protein interaction
protein purification
protein secondary structure
signal transduction
site directed mutagenesis
static electricity
catalysis
chemistry
genetics
metabolism
protein domain
protein motif
structure activity relation
X ray crystallography
Amino Acid Motifs
Catalysis
Crystallography, X-Ray
Humans
Indoleamine-Pyrrole 2,3,-Dioxygenase
Mutagenesis, Site-Directed
Protein Domains
Structure-Activity Relationship
description Human indoleamine 2,3-dioxygenase catalyzes the oxidative cleavage of tryptophan to N-formyl kynurenine, the initial and rate-limiting step in the kynurenine pathway. Additionally, this enzyme has been identified as a possible target for cancer therapy. A 20-amino acid protein segment (the JK loop), which connects the J and K helices, was not resolved in the reported hIDO crystal structure. Previous studies have shown that this loop undergoes structural rearrangement upon substrate binding. In this work, we apply a combination of replica exchange molecular dynamics simulations and site-directed mutagenesis experiments to characterize the structure and dynamics of this protein region. Our simulations show that the JK loop can be divided into two regions: the first region (JK loopC) displays specific and well-defined conformations and is within hydrogen bonding distance of the substrate, while the second region (JK loopN) is highly disordered and exposed to the solvent. The peculiar flexible nature of JK loopN suggests that it may function as a target for post-translational modifications and/or a mediator for protein-protein interactions. In contrast, hydrogen bonding interactions are observed between the substrate and Thr379 in the highly conserved "GTGG" motif of JK loopC, thereby anchoring JK loopC in a closed conformation, which secures the appropriate substrate binding mode for catalysis. Site-directed mutagenesis experiments confirm the key role of this residue, highlighting the importance of the JK loopC conformation in regulating the enzymatic activity. Furthermore, the existence of the partially and totally open conformations in the substrate-free form suggests a role of JK loopC in controlling substrate and product dynamics. © 2016 American Chemical Society.
format JOUR
author Álvarez, L.
Lewis-Ballester, A.
Roitberg, A.
Estrin, D.A.
Yeh, S.-R.
Marti, M.A.
Capece, L.
author_facet Álvarez, L.
Lewis-Ballester, A.
Roitberg, A.
Estrin, D.A.
Yeh, S.-R.
Marti, M.A.
Capece, L.
author_sort Álvarez, L.
title Structural Study of a Flexible Active Site Loop in Human Indoleamine 2,3-Dioxygenase and Its Functional Implications
title_short Structural Study of a Flexible Active Site Loop in Human Indoleamine 2,3-Dioxygenase and Its Functional Implications
title_full Structural Study of a Flexible Active Site Loop in Human Indoleamine 2,3-Dioxygenase and Its Functional Implications
title_fullStr Structural Study of a Flexible Active Site Loop in Human Indoleamine 2,3-Dioxygenase and Its Functional Implications
title_full_unstemmed Structural Study of a Flexible Active Site Loop in Human Indoleamine 2,3-Dioxygenase and Its Functional Implications
title_sort structural study of a flexible active site loop in human indoleamine 2,3-dioxygenase and its functional implications
url http://hdl.handle.net/20.500.12110/paper_00062960_v55_n19_p2785_Alvarez
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