PPMdb: a plant plasma membrane database.

PPMdb is a proteome database dedicated to proteins from plant plasma membranes. It provides comprehensive two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) maps, partial amino acid sequences and expression data. All this information is gathered and structured in a relational database, after being analyzed and annotated. PPMdb includes active links to related biological databases (EMBL, GenBank, GenPep, and SWISS-PROT and TrEMBL) as well as to MEDLINE abstracts. Information on specific protein spots can be displayed by clicking on the 2-D maps. In addition, users can query the database by accession number, protein name, pI and MW, and cellular location. Access to PPMdb is available at the following URL: http://sphinx.rug. ac.be:8080.