Annotation of glycoproteins in the SWISS-PROT database.

SWISS-PROT is a protein sequence database, which aims to be nonredundant, fully annotated and highly cross-referenced. Most eukaryotic gene products undergo co- and/or post-translational modifications, and these need to be included in the database in order to describe the mature protein. SWISS-PROT includes information on many types of different protein modifications. As glycosylation is the most common type of post-translational protein modification, we are currently placing an emphasis on annotation of protein glycosylation in SWISS-PROT. Information on the position of the sugar within the polypeptide chain, the reducing terminal linkage as well as additional information on biological function of the sugar is included in the database. In this paper we describe how we account for the different types of protein glycosylation, namely N-linked glycosylation, O-linked glycosylation, proteoglycans, C-linked glycosylation and the attachment of glycosyl-phosphatidylinosital anchors to proteins.