TrEMBL protein sequence database

Swiss-Prot, TrEMBL Annotated non-redundant protein sequence database, TrEMBL is a computer-annotated supplement to Swiss-Prot. TrEMBL contains the translations of all coding sequences present in the EMBL Nucleotide Sequence Database which are no yet integrated into Swiss-Prot... 

Bairoch A, Apweiler R (2000) The SWISS-PROT protein sequence database and its supplement TrEMBL in 2000. Nucleic Acids Res 28 45-48... 

The protein sequence databases are the most comprehensive source of information on proteins. The goal of this chapter is to describe the different protein sequence databases available to researchers. It is necessary to distinguish between universal databases that cover proteins from all species and specialized data collections that store information about specific families or groups of proteins, or about the proteins of a specific organism. Two categories of universal protein sequence databases can be discerned simple archives of sequence data and annotated databases in which additional information has been added to the sequence record. The next section describes the Protein Information Resource (PIR), the oldest protein sequence database SWISS-PROT, an annotated universal sequence database and TrEMBL, the supplement of... 

This section focuses on the use of SWISS-PROT + TrEMBL for sequence similarity searches. Searches in protein sequence databases have now become a standard research tool in the life sciences. To produce valuable results, the source databases should be comprehensive, nonredundant, well annotated, and up-to-date. However, lack of a single protein sequence database that satisfies all four criteria has previously forced users to perform searches across multiple databases to avoid incomplete results. This strategy normally produces complete but redundant results owing to different versions of the same sequence report in different databases. 

There are different classes of protein sequence databases. Primary and secondary databases are used to address different aspects of sequence analysis. Composite databases amalgamate a variety of different primary sources to facilitate sequence searching efficiently. The primary structure (amino acid sequence) of a protein is stored in primary databases as linear alphabets that represent the constituent residues. The secondary structure of a protein corresponding to region of local regularity (e.g., a-helices, /1-strands, and turns), which in sequence alignments are often apparent as conserved motifs, is stored in secondary databases as patterns. The tertiary structure of a protein derived from the packing of its secondary structural elements which may form folds and domains is stored in structure databases as sets of atomic coordinates. Some of the most important protein sequence databases are PIR (Protein Information Resource), SWISS-PROT (at EBI and ExPASy), MIPS (Munich Information Center for Protein Sequences), JIPID (Japanese International Protein Sequence Database), and TrEMBL (at EBI). ... 

SWISS-PROT (Bairoch and Apweiler, 2000) is a protein sequence database that, from its inception in 1986, was produced collaboratively by the Department of Medical Biochemistry at the University of Geneva and the EMBL. The database is now maintained collaboratively by Swiss Institute of Bioinformatics (SIB) and EBI/EMBL. SWISS-PROT provides high-level annotations, including descriptions of the function of the protein and of the structure of its domains, its post-translational modifications, its variants, and so on. The database can be accessed from http //expasy.hcuge.ch/sprot/sprot-top.html or numerous mirror sites. In 1966, Translated EMBL (TrEMBL) was created as a computer-annotated supplement to SWISS-PROT (Bleasby et al, 1994). 

SWISS-PROT (Hofmann et al., 1999) is a curated protein sequence database maintained by the Swiss Institute of Bioinfornmatics and is a collaborative partner of EMBL. The database consists of SWISS-PROT and TrEMBL, which consists of entries in SWISS-PROT-like format derived from the translation of all CDS in the... 

Introduction to Molecular Biology Databases. 1994-2004. R. Apweiler, R. Lopez, B. Marx, UniProt, SWISS-PROT, Switzerland. URL http //www.ebi.ac.uk/swissprot/Publications/ mbdl.html. Contents include bibliographic, taxonomy, nucleotide sequence, genetic, and protein sequence databases PIR, SWISS-PROT, and TrEMBL, and specialized protein, protein sequence, secondary protein, and structme databases. 

In 2002, UniProt consortium (http //www.uniprot.org) was formed by uniting the SWISS-PROT -I- TrEMBL and PIR-PSD activities by maintaining a high-quality database that serves as a stable, comprehensive, fully classified and accurately annotated protein sequence knowledge base (Figure 16.2). The database offers extensive cross-references and querying interfaces fuUy accessible to the scientific community (Bairoch et al., 2005). The UniProt consortium produces three layers of protein sequence databases ... 

The expansion of protein sequence databases, e.g. TrEMBL, SWISS-PROT, NCBInr brought about by genome sequencing projects, dcCTeases the probability of obtaining an imequivocal protein idenffication by PME alone [118], More information like amino add sequence or amino acid composition increases the confidence in any protein identification. Lahm s group [118] defined three ways to reduce this problem ... 

The increasing numbers of stored protein and nucleic acid sequences, and the recognition that functionally related proteins often had similar sequences, catalyzed the development of statistical techniques for sequence comparison which underlie many of the core bioinformatic methods used in proteomics today. Nucleic acid sequences are stored in three primary sequence databases - GenBank, the EMBL nucleotide sequence database, and the DNA database of Japan (DDBJ) - which exchange data every day. These databases also contain protein sequences that have been translated from DNA sequences. A dedicated protein sequence database, SWISS-PROT, was founded in 1986 and contains highly curated data concerning over 70 000 proteins. A related database, TrEMBL, contains automatic translations of the nucleotide sequences in the EMBL database and is not manually curated. 

MSDB (ftp //ftp.ncbi.nih.gov/repository/MSDB), database created especially for MS applications. Contains nonidentical protein sequences obtained from other databases (PIR, TrEMBL, SwissProt). At http // www.matrixscience.com/help/seq db setup msdb.html, a guidebook for MSDB users can be found. 

The SWISS-PROT and TrEMBL ID lines differ in the first two parts of the ID line. The first part is the entry name "ANP NOTCO" in the case of the SWISS-PROT example and "Q12757" in the TrEMBL example. The entry name used in all SP-TrEMBL entries is always the same as the accession number of the entry. The entry name used in REM-TrEMBL is the Protein ID tagged to the corresponding CDS in the EMBL Nucleotide Sequence Database. To the right of the entry name you will find either "preliminary" (in the TrEMBL entry) or STANDARD (in the SWISS-PROT entry). The data class used in TrEMBL is always PRELIMINARY. That means that the data are thoroughly checked by a computer,... 

The lower part shows information ofselected protein sequence. The small table shows the results of sequence search against UNIPROT(Swiss-prot/TrEMBL), nr.aa, and UniGene database see Subheading 2, items 2 and 4) using BLAST. 

The ExPASy server (www.expasy.chl is one of the most useful servers, where almost any bioinforma tic tool can be found, together with useful links to other websites such as NCBI or EBI. The several access databases are descriptive, easy to follow, and up to date. Protein data bank searches with SwissProt or Trembl, as well as sequence alignments using either SimAlign (for two sequences) or ClustalW (for more than two protein sequences) can be started from ExPASy, to name just a few of the possibilities available. Access is also given to the Roche Applied Science Biochemical pathways where either keyword searches for particular enzymes or for metabolites can be performed, or entire metabolic pathways or sections thereof can be visualized. Proteomics evaluation is also available on ExPASy, which features free 2D-PAGE software called Melanie. 

EMBL Nucleotide Sequence Database. SWISS-PROT consists of core sequence data with minimal redundancy, citation and extensive annotations including protein function, post-translational modifications, domain sites, protein structural information, diseases associated with protein deficiencies and variants. SWISS-PROT and TrEMBL are available at EBI site, http //www.ebi.ac.uk/swissprot/, and ExPASy site, http //www.expasy.ch/sprot/. From the SWISS-PROT and TrEMBL page of ExPASy site, click Full text search (under Access to SWISS-PROT and TrEMBL) to open the search page (Figure 11.3). Enter the keyword string (use Boolean expression if required), check SWISS-PROT box, and click the Submit button. Select the desired entry from the returned list to view the annotated sequence data in Swiss-Prot format. An output in the fasta format can be requested. Links to BLAST, feature table, some ExPASy proteomic tools (e.g., Compute pI/Mw, ProtParam, ProfileScan, ProtScale, PeptideMass, ScanProsite), and structure (SWISS-MODEL) are provided on the page. 

A variety of protein/DNA databases, such as GenBank, EMBL, NCBI, GenPept, Swiss-Prot, TrEMBL, PIR, OWL, IPI, and dbEST, are maintained by independent research groups for use by the public for proteome analysis. Databases have links to other databases and also provide vital information related to the identified proteins such as functions, any PTMs, domain and sites, 3D structures, homology to other proteins, associated diseases, sequence conflicts, and variants. 

Protein databases used to be from direct protein sequencing, but now they are made almost exclusively from the translation of ORFs (Open Reading Frames on DNA sequences). Both the European Bioinformatics Institute (EBI) and National Center for Biotechnology Information (NCBI) provide databases, TREMBL [15] and GENPEPT [19] respectively, which are automatic translations from the CDS features of the DNA in their nucleotide databases. This includes some automated annotation of the role which the protein plays. 

Nucleotide Sequence Database [26]) steps in. TrEMBL was created in 1996 and consists of computer-annotated entries in SWISS-PROT-like format. It is populated by protein sequences translated from the coding sequences (CDS) in EMBL and is a supplement to SWISS-PROT. In a way, it can be considered as a preliminary section of SWISS-PROT indeed, once the manual annotation is performed, the entries move on to SWISS-PROT. 

UniProt is a central repository of protein sequence and function created by joining the information contained in Swiss-Prot, TrEMBL, and PIR. UniProt is comprised of three components, each optimized for different uses. The UniProt Knowledgebase (UniProt) is the central access point for extensive curated protein information, including function, classification, and cross-reference. The UniProt Non-redundant Reference (UniRef) databases combine closely related sequences into a single record to speed searches. The UniProt Archive (UniParc) is a comprehensive repository, reflecting the history of all protein sequences. 

An ExPASy-TagIdent search was conducted to retrieve all bacterial proteins having an MW within 10 Da of the MW of the protein biomarker ion. In addition, the protein pi range of 0.00-14.00 was selected. Both UniProtKB/Swiss-Prot and UniProtKB/TrEMBL databases were included in the search. This search should retrieve hundreds of bacterial protein sequences in a single FASTA file. 

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