Development of databases accumulating information on regulatory processes is an important task of computational biology. The Transcription Regulatory Regions Database (TRRD) is a convenient tool for studying complex process of transcription regulation. The model of the functional organization of eukaryotic gene regulatory regions [1], is used as a basis for the TRRD database. The TRRD format [2] allows to describe the modular structure of transcription regulatory regions and the hierarchy of their constituent regulatory units. The TRRD database contains three interconnected tables: TRRDGENES (description of the genes as a whole), TRRDSITES (description of the sites), and TRRDBIB (references). The current version, TRRD 3.5, comprises the description of 427 genes, 607 regulatory units (promoters, enhancers, and silencers), and 2147 transcription factor binding sites. Over 1500 scientific publications were processed to obtain these data. The TRRDGENES database compiles the data on human (185 entries), mouse (126), rat (69), chicken (29), and other genes. The applet TRRD Viewer allows to visualize the data on the location of transcription factor binding sites in a map form and to overlook their textual description. The new release 4.0 (May 1998) will include a new module for describing the conditions under which a gene is expressed. These expression profiles consist of sets of vectors of expression data comprising information on cell cycle stage, developmental stage, cell type, tissue, organ, and the effect of external signals. The TRRD is installed under the SRS (http://sgi.sscc.ru), which provides easy information retrieval and TRRD integration with other databases and computer systems for data processing.

1. Kel' A.E. et al., 1997, Mol. Biol., v. 31, pp. 521-530.
2. Kel O.V., Proceedings of the 28th Annual Hawaii International Conference on System Sciences [HICSS], 1995, 5, Biotechnology Computing, IEE Computer Society Press: Los Alamos, California, pp. 42-51.