The archaeal transcription machinery shows high similarity with the eucaryal RNAP II system. Three archaeal homologues of eucaryal transcription factors, TBP (TATA box Binding Protein), TFB (Transcription Factor B) and the subunit of TFE (Transcription Factor E) have been found. Other transcription factors are believed to participate in archaeal transcription initiation. A protocol has been developed to selectively retrieve transcription related proteins from cell extract of the archaeon Pyrococcus furiosus (Pf). A number of proteins including the Pf TFB were retrieved from the cell extract and identified.
