Transcription factor IIIA (TF IIIA) binds and specifically activates transcription of eukaryotic 5S rRNA genes. It also forms a 7S ribonucleoprotein complex with mature 5S rRNA. Here, we describe the purification and properties of pTF IIIA from higher plants. The purified protein from tulip (Tulipa whittalii) has a molecular mass of about 40 kDa and also binds 5S rRNA and 5S rRNA genes. pTF IIIA also facilitates the transcription of a 5S rRNA gene in a HeLa cell extract.