RegulonDB (version 2.0): a database on transcriptional regulation in Escherichia coli

RegulonDB version 2,0, a database on transcriptional regulation and operon organization in Escherichia coli, is now available on the web at the follow ing URL:http://www.cifn.unam.mx/Computational_Biology/regulondb/, In this p aper we describe the main computational changes to the database, which incl ude migrating the database to Sybase, providing graphical descriptions of t he internal organization of operons and regulons, and direct links to MEDLI NE references. The web interface offers searching either by mechanisms of r egulation or by operon organization. The results of a search (operon organi zation, or site collection) are displayed as hypertext, and can also be dis played graphically, In terms of its contents, RegulonDB contains a targe nu mber of operons, as well as the absolute position in the completed genome s equence of sites, promoters, and individual genes of E.coli.