Structure and function of transcription factors.

The expression of many genes is regulated at the level of transcription initiation. Technological advances over the last few years have led to new insights into the mechanism of initiation and the different ways that it can be modulated. Many of the proteins involved have now been identified and in some cases extensively characterised. Some of these proteins or transcription factors bind to specific DNA elements either alone or in collaboration with other proteins, often resulting in stimulation of transcription initiation. An understanding of how these factors function, therefore, is essential to understanding the transcription 'process' and how it is regulated. Domains within some of these factors that are responsible for DNA interaction and transcriptional activation have been identified by a combination of genetic, biochemical and physical approaches and these studies are beginning to provide valuable information concerning the possible mechanisms that can regulate their activity. The transcription process itself is highly conserved, many of the components being interchangeable between yeast and man.