Members of this family are approximately 26 KDa, and are involved in trans-activator of late transcription [1].

1: The A2L intermediate gene product is required for in vitro transcription from a vaccinia virus late promoter. Hubbs AE, Wright CF; J Virol 1996;70:327-331. PMID:8523544

2: Evolutionary genomics of nucleo-cytoplasmic large DNA viruses. Iyer LM, Balaji S, Koonin EV, Aravind L; Virus Res. 2006;117:156-184. PMID:16494962