Protein family
Archaeal transcription factor B (ATFB or TFB) is a protein family of extrinsic transcription factors that guide the initiation of RNA transcription in organisms that fall under the domain of Archaea.[1] It is homologous to eukaryotic TFIIB and, more distantly, to bacterial sigma factor.[2] Like these proteins, it is involved in forming transcription preinitiation complexes.[3] Its structure includes several conserved motifs which interact with DNA and other transcription factors, notably the single type of RNA polymerase that performs transcription in Archaea.[1]