Transcription termination factor essential for chloroplast development. Required for maturation of 16S rRNA, 18S rRNA and 23S rRNA in the chloroplast. Binds to a specific region within the tRNA(Ile)(GAU) gene at a position adjacent to and downstream of the 16S rRNA gene. Required for the maturation of tRNA(Ile)(GAU). Binds to double-stranded DNA. A number of isoforms are produced. According to EST sequences. Small white seeds, with defective choloroplasts, that are unable to germinate on soil. Albino seedlings that die rapidly when grown on synthetic medium. Belongs to the mTERF family.