Database schemes. Panel A shows the scheme of the species-specific databases. Panel B shows the scheme followed by PlantTFDB. Nine tables structure the information stored in the species-centered databases. A: The tables sequences, present domains, orthologs and ESTs are connected to each other and to the table TFs by means of the cds_id field. The table domain_algn stores the alignments at the domain level for the members of a given family. All five tables contain information about the TFs. The tables families, relevant domains and papers are connected to each other and to the table TFs by means of the field family_id. They store the information concerning the TF families. B: A single table structures the information for Plant TFDB. Table names appear in blue background, and main keys in green background.