RESUMEN
Rearrangements of about 2.5 kilobases of regulatory DNA located 5' of the transcription start site of the Drosophila even-skipped locus generate large-scale changes in the expression of even-skipped stripes 2, 3, and 7. The most radical effects are generated by juxtaposing the minimal stripe enhancers MSE2 and MSE3 for stripes 2 and 3 with and without small "spacer" segments less than 360 bp in length. We placed these fusion constructs in a targeted transformation site and obtained quantitative expression data for these transformants together with their controlling transcription factors at cellular resolution. These data demonstrated that the rearrangements can alter expression levels in stripe 2 and the 2-3 interstripe by a factor of more than 10. We reasoned that this behavior would place tight constraints on possible rules of genomic cis-regulatory logic. To find these constraints, we confronted our new expression data together with previously obtained data on other constructs with a computational model. The model contained representations of thermodynamic protein-DNA interactions including steric interference and cooperative binding, short-range repression, direct repression, activation, and coactivation. The model was highly constrained by the training data, which it described within the limits of experimental error. The model, so constrained, was able to correctly predict expression patterns driven by enhancers for other Drosophila genes; even-skipped enhancers not included in the training set; stripe 2, 3, and 7 enhancers from various Drosophilid and Sepsid species; and long segments of even-skipped regulatory DNA that contain multiple enhancers. The model further demonstrated that elevated expression driven by a fusion of MSE2 and MSE3 was a consequence of the recruitment of a portion of MSE3 to become a functional component of MSE2, demonstrating that cis-regulatory "elements" are not elementary objects.
Asunto(s)
Proteínas de Drosophila/genética , Drosophila melanogaster , Elementos de Facilitación Genéticos , Reordenamiento Génico/genética , Proteínas de Homeodominio/genética , Factores de Transcripción/genética , Animales , Sitios de Unión , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Evolución Molecular , Regulación del Desarrollo de la Expresión Génica , Genoma , ARN no Traducido/genética , Sitio de Iniciación de la TranscripciónRESUMEN
The EUROCarbDB project is a design study for a technical framework, which provides sophisticated, freely accessible, open-source informatics tools and databases to support glycobiology and glycomic research. EUROCarbDB is a relational database containing glycan structures, their biological context and, when available, primary and interpreted analytical data from high-performance liquid chromatography, mass spectrometry and nuclear magnetic resonance experiments. Database content can be accessed via a web-based user interface. The database is complemented by a suite of glycoinformatics tools, specifically designed to assist the elucidation and submission of glycan structure and experimental data when used in conjunction with contemporary carbohydrate research workflows. All software tools and source code are licensed under the terms of the Lesser General Public License, and publicly contributed structures and data are freely accessible. The public test version of the web interface to the EUROCarbDB can be found at http://www.ebi.ac.uk/eurocarb.
Asunto(s)
Carbohidratos/química , Bases de Datos como Asunto , Programas Informáticos , Animales , Conformación de Carbohidratos , Biología Computacional , Glicómica , Humanos , Modelos Moleculares , Peso Molecular , Sistemas en LíneaRESUMEN
The Worldwide Protein Data Bank (wwPDB; wwpdb.org) is the international collaboration that manages the deposition, processing and distribution of the PDB archive. The online PDB archive at ftp://ftp.wwpdb.org is the repository for the coordinates and related information for more than 47 000 structures, including proteins, nucleic acids and large macromolecular complexes that have been determined using X-ray crystallography, NMR and electron microscopy techniques. The members of the wwPDB-RCSB PDB (USA), MSD-EBI (Europe), PDBj (Japan) and BMRB (USA)-have remediated this archive to address inconsistencies that have been introduced over the years. The scope and methods used in this project are presented.
Asunto(s)
Bases de Datos de Proteínas , Sustancias Macromoleculares/química , Archivos , Cristalografía por Rayos X , Bases de Datos de Proteínas/normas , Diccionarios Químicos como Asunto , Internet , Microscopía Electrónica , Resonancia Magnética Nuclear Biomolecular , Ácidos Nucleicos/química , Proteínas/química , Reproducibilidad de los Resultados , Terminología como AsuntoRESUMEN
To address data management and data exchange problems in the nuclear magnetic resonance (NMR) community, the Collaborative Computing Project for the NMR community (CCPN) created a "Data Model" that describes all the different types of information needed in an NMR structural study, from molecular structure and NMR parameters to coordinates. This paper describes the development of a set of software applications that use the Data Model and its associated libraries, thus validating the approach. These applications are freely available and provide a pipeline for high-throughput analysis of NMR data. Three programs work directly with the Data Model: CcpNmr Analysis, an entirely new analysis and interactive display program, the CcpNmr FormatConverter, which allows transfer of data from programs commonly used in NMR to and from the Data Model, and the CLOUDS software for automated structure calculation and assignment (Carnegie Mellon University), which was rewritten to interact directly with the Data Model. The ARIA 2.0 software for structure calculation (Institut Pasteur) and the QUEEN program for validation of restraints (University of Nijmegen) were extended to provide conversion of their data to the Data Model. During these developments the Data Model has been thoroughly tested and used, demonstrating that applications can successfully exchange data via the Data Model. The software architecture developed by CCPN is now ready for new developments, such as integration with additional software applications and extensions of the Data Model into other areas of research.
Asunto(s)
Bases de Datos de Proteínas , Espectroscopía de Resonancia Magnética/métodos , Programas Informáticos , Gráficos por Computador , Espectroscopía de Resonancia Magnética/instrumentación , Modelos TeóricosRESUMEN
Data management has emerged as one of the central issues in the high-throughput processes of taking a protein target sequence through to a protein sample. To simplify this task, and following extensive consultation with the international structural genomics community, we describe here a model of the data related to protein production. The model is suitable for both large and small facilities for use in tracking samples, experiments, and results through the many procedures involved. The model is described in Unified Modeling Language (UML). In addition, we present relational database schemas derived from the UML. These relational schemas are already in use in a number of data management projects.
Asunto(s)
Genómica/métodos , Ingeniería de Proteínas/métodos , Proteínas/química , Proteómica/métodos , Algoritmos , Secuencia de Aminoácidos , Interpretación Estadística de Datos , Bases de Datos de Proteínas , Internet , Modelos Biológicos , Lenguajes de Programación , Investigación , Programas Informáticos , Diseño de Software , Biología de Sistemas , Unified Medical Language SystemRESUMEN
In recent years the amount of biological data has exploded to the point where much useful information can only be extracted by complex computational analyses. Such analyses are greatly facilitated by metadata standards, both in terms of the ability to compare data originating from different sources, and in terms of exchanging data in standard forms, e.g. when running processes on a distributed computing infrastructure. However, standards thrive on stability whereas science tends to constantly move, with new methods being developed and old ones modified. Therefore maintaining both metadata standards, and all the code that is required to make them useful, is a non-trivial problem. Memops is a framework that uses an abstract definition of the metadata (described in UML) to generate internal data structures and subroutine libraries for data access (application programming interfaces--APIs--currently in Python, C and Java) and data storage (in XML files or databases). For the individual project these libraries obviate the need for writing code for input parsing, validity checking or output. Memops also ensures that the code is always internally consistent, massively reducing the need for code reorganisation. Across a scientific domain a Memops-supported data model makes it easier to support complex standards that can capture all the data produced in a scientific area, share them among all programs in a complex software pipeline, and carry them forward to deposition in an archive. The principles behind the Memops generation code will be presented, along with example applications in Nuclear Magnetic Resonance (NMR) spectroscopy and structural biology.
Asunto(s)
Biología Computacional/métodos , Bases de Datos Factuales , Procesamiento Automatizado de Datos , Programas Informáticos , Espectroscopía de Resonancia Magnética/normas , Estándares de ReferenciaRESUMEN
The PDB ligand dictionary is the chemical reference database of all the small building block molecules (e.g., amino acids, nucleic acids, and bound ligands) in the Protein Data Bank (PDB) referenced by a distinct three-letter code identifier. Since PDB files have only three-dimensional coordinate data, the role of the dictionary that of a reference resource for the actual chemical properties of small molecules, shared consistently across all PDB entries. The ligand dictionary is maintained in all sites of the Worldwide Protein Data Bank (wwPDB), the Research Collaboratory for Structural Bioinformatics (RCSB) in U.S., the Macromolecular Structure Database (MSD) in Europe, and the Protein Data Bank in Japan (PDBj), and it is exchanged on a regular basis. The MSD group at the European BioInformatics Institute (EBI) extends the dictionary into the MSDchem ligand database, which utilizes chemo-informatics packages and incorporates additional curation work. MSDchem is publicly available on the Web through the MSDchem search system, the functionality of which is described in more detail in this unit.
Asunto(s)
Sistemas de Administración de Bases de Datos , Bases de Datos de Proteínas , Diccionarios Químicos como Asunto , Almacenamiento y Recuperación de la Información/métodos , Ligandos , Mapeo de Interacción de Proteínas/métodos , Proteínas/química , Sitios de Unión , Unión Proteica , Interfaz Usuario-ComputadorRESUMEN
MOTIVATION: The lack of standards for storage and exchange of data is a serious hindrance for the large-scale data deposition, data mining and program interoperability that is becoming increasingly important in bioinformatics. The problem lies not only in defining and maintaining the standards, but also in convincing scientists and application programmers with a wide variety of backgrounds and interests to adhere to them. RESULTS: We present a UML-based programming framework for the modeling of data and the automated production of software to manipulate that data. Our approach allows one to make an abstract description of the structure of the data used in a particular scientific field and then use it to generate fully functional computer code for data access and input/output routines for data storage, together with accompanying documentation. This code can be generated simultaneously for different programming languages from a single model, together with, for example for format descriptions and I/O libraries XML and various relational databases. The framework is entirely general and could be applied in any subject area. We have used this approach to generate a data exchange standard for structural biology and analysis software for macromolecular NMR spectroscopy. AVAILABILITY: The framework is available under the GPL license, the data exchange standard with generated subroutine libraries under the LGPL license. Both may be found at http://www.ccpn.ac.uk; http://sourceforge.net/projects/ccpn CONTACT: ccpn@mole.bio.cam.ac.uk.
Asunto(s)
Biopolímeros/química , Sistemas de Administración de Bases de Datos , Documentación/métodos , Almacenamiento y Recuperación de la Información/métodos , Modelos Biológicos , Modelos Químicos , Programas Informáticos , Unified Medical Language System , Biopolímeros/análisis , Biopolímeros/clasificación , Biopolímeros/metabolismo , Simulación por Computador , Documentación/normas , Guías como Asunto , Espectroscopía de Resonancia Magnética/métodos , Espectroscopía de Resonancia Magnética/normas , Estándares de Referencia , Ciencia/métodosRESUMEN
A recent workshop discusses the progress toward integrating NMR data into a unifying data model.