PROSITE is a database of protein sequence patterns and sites, developed since 1988 to help determine protein function through sequence analysis. It contains 605 different patterns in its 1992 release, with documentation for each pattern. The database is composed of two ASCII files: PROSITE.DAT, which contains computational information for pattern scanning, and PROSITE.DOC, which provides textual documentation. Patterns are reviewed periodically to ensure their relevance. PROSITE is distributed by the EMBL Data Library and can be accessed via FTP or other online services. The database includes patterns for various protein families, such as DNA polymerase family B, which is characterized by a conserved tetrapeptide. The database also includes information on post-translational modifications, domains, enzymes, and other protein-related features. PROSITE is a valuable resource for researchers in bioinformatics and molecular biology.PROSITE is a database of protein sequence patterns and sites, developed since 1988 to help determine protein function through sequence analysis. It contains 605 different patterns in its 1992 release, with documentation for each pattern. The database is composed of two ASCII files: PROSITE.DAT, which contains computational information for pattern scanning, and PROSITE.DOC, which provides textual documentation. Patterns are reviewed periodically to ensure their relevance. PROSITE is distributed by the EMBL Data Library and can be accessed via FTP or other online services. The database includes patterns for various protein families, such as DNA polymerase family B, which is characterized by a conserved tetrapeptide. The database also includes information on post-translational modifications, domains, enzymes, and other protein-related features. PROSITE is a valuable resource for researchers in bioinformatics and molecular biology.