Transcription-associated protein families are primarily taxon-specific

The mechanisms controlling gene regulation appear to be fundamentally diffe rent in eukaryotes and prokaryotes (Struhl (1999) Cell, 98, 1-4). To invest igate this diversity further, we have analysed the distribution of all know n transcription-associated proteins (TAPs), as reflected by sequence databa se annotations. Our results for the primary phylogenetic domains (Archaea, Bacteria and Eukaryota) show that TAP families are mostly taxon-specific an d very few transcriptional regulators are common across these domains.