Eukaryotic transcription factors: Identification, characterization and functions

Eukaryotic transcription factors are modular proteins that utilize distinct domains for transcriptional activation (or repression) and DNA binding. The highly specific interaction between a given transcription factor and its cognate binding sequence forms the basis for the biochemical characterization and eventual purification of these important regulatory proteins. Commonly used techniques in the assessment of DNA binding of a transcription factor include EMSA and DNase I protection (footprinting) assay. Transcription factors are often purified and cloned based on their specific binding sequences. Finally, several important classes of structural motifs present in many eukaryotic transcription factors are presented. The understanding of the structure and function relationship between transcription factors and the genes that they regulate should provide the basis for understanding the overall molecular mechanisms controlling gene expression.