SWISS-PROT is a curated protein sequence database that provides high-quality annotations, including function, structure, post-translational modifications, and disease associations. It aims to minimize redundancy and integrate with other databases. TrEMBL, a computer-annotated supplement to SWISS-PROT, is derived from the translation of all coding sequences (CDS) in the EMBL nucleotide sequence database, excluding those already in SWISS-PROT. SWISS-PROT distinguishes itself through its detailed annotations, which include function, post-translational modifications, domains, secondary and quaternary structures, similarities to other proteins, and disease associations. Annotations are primarily found in comment lines, feature tables, and keyword lines. The database also minimizes redundancy by merging data from different sources and provides cross-references to other databases such as EMBL, PDB, OMIM, and PROSITE. Recent developments include the inclusion of sequences from a wide range of model organisms, such as Arabidopsis thaliana, Caenorhabditis elegans, and Homo sapiens, and the addition of new documentation files. TrEMBL has been introduced to handle the increasing volume of protein sequences, with entries automatically annotated using PROSITE patterns and the ENZYME database. TrEMBL is divided into two sections: SP-TrEMBL, which contains entries to be incorporated into SWISS-PROT, and REM-TrEMBL, which contains entries not suitable for inclusion in SWISS-PROT, such as immunoglobulins, synthetic sequences, and fragments. SWISS-PROT is distributed on CD-ROM by the EMBL Outstation – The European Bioinformatics Institute and is available via FTP and the World-Wide Web. It is updated regularly, with four releases per year and weekly updates. The database is freely available for use and redistribution.SWISS-PROT is a curated protein sequence database that provides high-quality annotations, including function, structure, post-translational modifications, and disease associations. It aims to minimize redundancy and integrate with other databases. TrEMBL, a computer-annotated supplement to SWISS-PROT, is derived from the translation of all coding sequences (CDS) in the EMBL nucleotide sequence database, excluding those already in SWISS-PROT. SWISS-PROT distinguishes itself through its detailed annotations, which include function, post-translational modifications, domains, secondary and quaternary structures, similarities to other proteins, and disease associations. Annotations are primarily found in comment lines, feature tables, and keyword lines. The database also minimizes redundancy by merging data from different sources and provides cross-references to other databases such as EMBL, PDB, OMIM, and PROSITE. Recent developments include the inclusion of sequences from a wide range of model organisms, such as Arabidopsis thaliana, Caenorhabditis elegans, and Homo sapiens, and the addition of new documentation files. TrEMBL has been introduced to handle the increasing volume of protein sequences, with entries automatically annotated using PROSITE patterns and the ENZYME database. TrEMBL is divided into two sections: SP-TrEMBL, which contains entries to be incorporated into SWISS-PROT, and REM-TrEMBL, which contains entries not suitable for inclusion in SWISS-PROT, such as immunoglobulins, synthetic sequences, and fragments. SWISS-PROT is distributed on CD-ROM by the EMBL Outstation – The European Bioinformatics Institute and is available via FTP and the World-Wide Web. It is updated regularly, with four releases per year and weekly updates. The database is freely available for use and redistribution.