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Biomedical subjects

N Redaschi

Publications and source records attributed to N Redaschi.

4 recordsLinked to original sources

The EMBL nucleotide sequence database.

The EMBL Nucleotide Sequence Database (http://www.ebi.ac.uk/embl/) is maintained at the European Bioinformatics Institute (EBI) in an international collaboration with the DNA Data Bank of Japan (DDBJ) and GenBank at the NCBI (USA). Data is exchanged amongst the collaborating databases on a daily basis. The major contributors to the EMBL database are individual authors and genome project groups. Webin is the preferred web-based submission system for individual submitters, whilst automatic procedures allow incorporation of sequence data from large-scale genome sequencing centres and from the European Patent Office (EPO). Database releases are produced quarterly. Network services allow free access to the most up-to-date data collection via ftp, email and World Wide Web interfaces. EBI's Sequence Retrieval System (SRS), a network browser for databanks in molecular biology, integrates and links the main nucleotide and protein databases plus many specialized databases. For sequence similarity searching a variety of tools (e.g. Blitz, Fasta, BLAST) are available which allow external users to compare their own sequences against the latest data in the EMBL Nucleotide Sequence Database and SWISS-PROT.

Computational Biology↗

Accessing and distributing EMBL data using CORBA (common object request broker architecture).

BACKGROUND: The EMBL Nucleotide Sequence Database is a comprehensive database of DNA and RNA sequences and related information traditionally made available in flat-file format. Queries through tools such as SRS (Sequence Retrieval System) also return data in flat-file format. Flat files have a number of shortcomings, however, and the resources therefore currently lack a flexible environment to meet individual researchers' needs. The Object Management Group's common object request broker architecture (CORBA) is an industry standard that provides platform-independent programming interfaces and models for portable distributed object-oriented computing applications. Its independence from programming languages, computing platforms and network protocols makes it attractive for developing new applications for querying and distributing biological data. RESULTS: A CORBA infrastructure developed by EMBL-EBI provides an efficient means of accessing and distributing EMBL data. The EMBL object model is defined such that it provides a basis for specifying interfaces in interface definition language (IDL) and thus for developing the CORBA servers. The mapping from the object model to the relational schema in the underlying Oracle database uses the facilities provided by PersistenceTM, an object/relational tool. The techniques of developing loaders and 'live object caching' with persistent objects achieve a smart live object cache where objects are created on demand. The objects are managed by an evictor pattern mechanism. CONCLUSIONS: The CORBA interfaces to the EMBL database address some of the problems of traditional flat-file formats and provide an efficient means for accessing and distributing EMBL data. CORBA also provides a flexible environment for users to develop their applications by building clients to our CORBA servers, which can be integrated into existing systems.

Computational Biology↗

Posttranscriptional regulation of EcoP1I and EcoP15I restriction activity.

Efficient establishment of a DNA restriction-modification (R-M) system in a non-modified cell requires a tight control of the potentially lethal activity of the restriction enzyme. The type III R-M systems EcoP1I and EcoP15I can be transferred to non-modified Escherichia coli cells by transfection, conjugation or transformation and become established without difficulty. Modification activity is expressed immediately after the R-M genes enter the cell, whereas the expression of restriction activity is delayed until complete protection of the cellular DNA is achieved by methylation. We have shown by Western blot analysis that the expression of the modification polypeptide subunit positively regulates the amount of restriction subunit present in the cell. The finding that ribosomal alterations affected the expression of restriction activity pointed to additional control at the translational level. The analysis of EcoP1I expression in E. coli strains mutated in either of the ribosomal proteins S12 (rpsL) or S4 (rpsD) suggests that the level of in vivo restriction activity can be modulated both by a decrease in the efficiency of translation and by varying ribosomal accuracy conditions. In addition, we have preliminary evidence from in vivo gene fusion studies that the res gene may code for more than one gene product.

Anti-Bacterial Agents↗

FastAlert--an automatic search system to alert about new entries in biological sequence databanks.

This paper describes a new tool enabling awareness of new sequence databank entries of interest. The FastAlert system relieves the researcher from the burden of repeating FASTA searches in order to keep up with the rapidly growing amount of information found in biological sequence databanks. The query sequence can be submitted from any computer connected to the Internet. Upon registration, the databank, including the updates, is scanned at periodic intervals with the sequence provided. The results, so-called FastAlert reports, are delivered via electronic mail. The reports contain the FASTA best-scores list and the similarity statistics for each entry listed.

Amino Acid Sequence↗