FttA is a CPSF73 homologue that terminates transcription in Archaea.

Regulated gene expression is largely achieved by controlling the activities of essential, multisubunit RNA polymerase transcription elongation complexes (TECs). The extreme stability required of TECs to processively transcribe large genomic regions necessitates robust mechanisms to terminate transcription. Efficient transcription termination is particularly critical for gene-dense bacterial and archaeal genomes in which continued transcription would necessarily transcribe immediately adjacent genes and result in conflicts between the transcription and replication apparatuses; the coupling of transcription and translation would permit the loading of ribosomes onto aberrant transcripts.