A class of proteins related in structure and function to TATA-BOX BINDING PROTEIN that can take the place of TATA-BOX BINDING PROTEIN in the transcription initiation complex. They are found in most multicellular organisms and may be involved in tissue-specific promoter regulation. They bind to DNA and interact with TATA-BINDING PROTEIN ASSOCIATED FACTORS, however they may lack specificity for the TATA-BOX.
