Structural analysis of macromolecular folds and the application to phasing

[eng] Determining and understanding protein structure in atomic detail is a fundamental process to the advancement of biotechnology and biomedicine, shedding light the role of macromolecules and their complexes, their biological functions and pathways. The work presented in this thesis contributes t...

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Detalles Bibliográficos
Autor: Medina Bernal, Ana del Rocío
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/182200
Acceso en línea:https://hdl.handle.net/2445/182200
http://hdl.handle.net/10803/673056
Access Level:acceso abierto
Palabra clave:Biologia molecular
Bioinformàtica
Macromolècules
Cristal·lografia
Estructura cristal·lina (Sòlids)
Molecular biology
Bioinformatics
Macromolecules
Crystallography
Layer structure (Solids)
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spelling Structural analysis of macromolecular folds and the application to phasingMedina Bernal, Ana del RocíoBiologia molecularBioinformàticaMacromolèculesCristal·lografiaEstructura cristal·lina (Sòlids)Molecular biologyBioinformaticsMacromoleculesCrystallographyLayer structure (Solids)[eng] Determining and understanding protein structure in atomic detail is a fundamental process to the advancement of biotechnology and biomedicine, shedding light the role of macromolecules and their complexes, their biological functions and pathways. The work presented in this thesis contributes to this aim by exploring new ways of identifying, analysing and classifying small, disconnected fragments and their association into local folds to provide specialised input models for X-ray crystallography phasing methods and as a general structural bioinformatics tool to enrich our insight of the results. The first part of this work has developed algorithms capturing the complexity of the backbone atoms by the use of geometric descriptors called Characteristic Vectors. The context of each amino acid is abstracted into a vector. The method encodes structural properties in a graph, whose exploration allows performing secondary and tertiary structure annotation, decomposition of a structure into compact local folds, fragment comparison and superposition, generation of fragment libraries from geometrical constraints, and the identification and classification of protein interfaces and new unique local folds. The results of this thesis have been implemented in the program ALEPH. ALEPH is also deeply integrated within the ARCIMBOLDO framework as a bioinformatics tool used in multiple contexts, fundamentally providing model hypotheses for fragment-based phasing. In ARCIMBOLDO small and accurate fragments are placed with Phaser and solutions are identified and expanded to the full structure via density modification and auto- tracing within SHELXE. In addition, in this work, new strategies addressing multimeric structures have been developed. Multimers are very frequent and their presence increases the complexity of the structure to be determined, especially for fragment-based approaches that must rely on a very small percentage of the total scattering. The problem has been successfully overcome in a computationally efficient way. The usefulness of the methods developed has been established in their practical application to 10 previously unknown macromolecular structures. Very recently, new efficient and powerful computational approaches based on deep-learning have made a breakthrough in the accuracy of three-dimensional models predicted from the sequence. As of July 2021, the tools to compute such models have been made available. We did not want to conclude this work, without a preliminary exploration on the use of AlphaFold2 and RoseTTAFold models in the context of phasing with small fragments. ALEPH and ARCIMBOLDO and their graphical user interfaces have been distributed worldwide and have been successfully used in their published work by independent groups and collaborators.Universitat de BarcelonaUsón Finkenzeller, IsabelSammito, Massimo DomenicoUniversitat de Barcelona. Facultat de Farmàcia i Ciències de l'Alimentació2021info:eu-repo/semantics/doctoralThesisinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/182200http://hdl.handle.net/10803/673056Tesis Doctorals - Facultat - Farmàcia i Ciències de l'Alimentacióreponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaIngléscc by-nc-sa (c) Medina Bernal, Ana del Rocío, 2021http://creativecommons.org/licenses/by-nc-sa/3.0/es/info:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/1822002026-05-27T06:46:51Z
dc.title.none.fl_str_mv Structural analysis of macromolecular folds and the application to phasing
title Structural analysis of macromolecular folds and the application to phasing
spellingShingle Structural analysis of macromolecular folds and the application to phasing
Medina Bernal, Ana del Rocío
Biologia molecular
Bioinformàtica
Macromolècules
Cristal·lografia
Estructura cristal·lina (Sòlids)
Molecular biology
Bioinformatics
Macromolecules
Crystallography
Layer structure (Solids)
title_short Structural analysis of macromolecular folds and the application to phasing
title_full Structural analysis of macromolecular folds and the application to phasing
title_fullStr Structural analysis of macromolecular folds and the application to phasing
title_full_unstemmed Structural analysis of macromolecular folds and the application to phasing
title_sort Structural analysis of macromolecular folds and the application to phasing
dc.creator.none.fl_str_mv Medina Bernal, Ana del Rocío
author Medina Bernal, Ana del Rocío
author_facet Medina Bernal, Ana del Rocío
author_role author
dc.contributor.none.fl_str_mv Usón Finkenzeller, Isabel
Sammito, Massimo Domenico
Universitat de Barcelona. Facultat de Farmàcia i Ciències de l'Alimentació
dc.subject.none.fl_str_mv Biologia molecular
Bioinformàtica
Macromolècules
Cristal·lografia
Estructura cristal·lina (Sòlids)
Molecular biology
Bioinformatics
Macromolecules
Crystallography
Layer structure (Solids)
topic Biologia molecular
Bioinformàtica
Macromolècules
Cristal·lografia
Estructura cristal·lina (Sòlids)
Molecular biology
Bioinformatics
Macromolecules
Crystallography
Layer structure (Solids)
description [eng] Determining and understanding protein structure in atomic detail is a fundamental process to the advancement of biotechnology and biomedicine, shedding light the role of macromolecules and their complexes, their biological functions and pathways. The work presented in this thesis contributes to this aim by exploring new ways of identifying, analysing and classifying small, disconnected fragments and their association into local folds to provide specialised input models for X-ray crystallography phasing methods and as a general structural bioinformatics tool to enrich our insight of the results. The first part of this work has developed algorithms capturing the complexity of the backbone atoms by the use of geometric descriptors called Characteristic Vectors. The context of each amino acid is abstracted into a vector. The method encodes structural properties in a graph, whose exploration allows performing secondary and tertiary structure annotation, decomposition of a structure into compact local folds, fragment comparison and superposition, generation of fragment libraries from geometrical constraints, and the identification and classification of protein interfaces and new unique local folds. The results of this thesis have been implemented in the program ALEPH. ALEPH is also deeply integrated within the ARCIMBOLDO framework as a bioinformatics tool used in multiple contexts, fundamentally providing model hypotheses for fragment-based phasing. In ARCIMBOLDO small and accurate fragments are placed with Phaser and solutions are identified and expanded to the full structure via density modification and auto- tracing within SHELXE. In addition, in this work, new strategies addressing multimeric structures have been developed. Multimers are very frequent and their presence increases the complexity of the structure to be determined, especially for fragment-based approaches that must rely on a very small percentage of the total scattering. The problem has been successfully overcome in a computationally efficient way. The usefulness of the methods developed has been established in their practical application to 10 previously unknown macromolecular structures. Very recently, new efficient and powerful computational approaches based on deep-learning have made a breakthrough in the accuracy of three-dimensional models predicted from the sequence. As of July 2021, the tools to compute such models have been made available. We did not want to conclude this work, without a preliminary exploration on the use of AlphaFold2 and RoseTTAFold models in the context of phasing with small fragments. ALEPH and ARCIMBOLDO and their graphical user interfaces have been distributed worldwide and have been successfully used in their published work by independent groups and collaborators.
publishDate 2021
dc.date.none.fl_str_mv 2021
dc.type.none.fl_str_mv info:eu-repo/semantics/doctoralThesis
info:eu-repo/semantics/publishedVersion
format doctoralThesis
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/182200
http://hdl.handle.net/10803/673056
url https://hdl.handle.net/2445/182200
http://hdl.handle.net/10803/673056
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.rights.none.fl_str_mv cc by-nc-sa (c) Medina Bernal, Ana del Rocío, 2021
http://creativecommons.org/licenses/by-nc-sa/3.0/es/
info:eu-repo/semantics/openAccess
rights_invalid_str_mv cc by-nc-sa (c) Medina Bernal, Ana del Rocío, 2021
http://creativecommons.org/licenses/by-nc-sa/3.0/es/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Universitat de Barcelona
publisher.none.fl_str_mv Universitat de Barcelona
dc.source.none.fl_str_mv Tesis Doctorals - Facultat - Farmàcia i Ciències de l'Alimentació
reponame:Dipòsit Digital de la UB
instname:Universidad de Barcelona
instname_str Universidad de Barcelona
reponame_str Dipòsit Digital de la UB
collection Dipòsit Digital de la UB
repository.name.fl_str_mv
repository.mail.fl_str_mv
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