The plasmid genome database.

The Plasmid Genome Database (PGD) is a regularly updated collection of all fully sequenced plasmids (approaching 500 as of May 2003) with links to structural maps of each plasmid (http://www. genomics.ceh.ac.uk/plasmiddb/). The amount of whole genome and whole plasmid sequence data has been growing exponentially (see Fig. 1), generating enormous amounts of data that, if the information can be arranged in a comprehensive and structural way, represent a major resource for many researchers. To our knowledge, this is the first database that has collated all fully sequenced plasmids, including core features, their genetic composition and structural maps (Wackett, 2002).