TFD: The transcription factors database

Since its inception (1), a number of changes (2) have occurred to the Transcription Factors Database, some details of which will be described here. This database is designed to capture and contain information about the properties of transcription factors, their interrelationships, the nucleic acid and amino acid sequences that encode them, and the DNA sequences they recognize. This information has been sequestered into different tables so that, through the use of relational database management systems, the existence of relationships between the various entities represented in the database may be apprehended. Figure 1 presents an ERD (Entity-Relationship Diagram), and Figure 2 the corresponding data dictionary, for release 4. 2 of this database, which became available in February 1992. Since release 1. 0, five new tables (METHODS, NPOINTERS, POLYPEPTIDES, REFERENCES, and XPOINTERS) have been added, one table (ELEMENTS) has been removed, and the name of one table has been changed (from CDNAS to CLONES). The reference number (ref n) fields in the various tables have been maintained from the original database definition, but these fields now contain a Medline Unique Identifier (UID), avoiding the need for maintaining a local reference numbering scheme. In release 4. 2,