This represents a conserved region within a number of RAD3-like DNA-binding helicases that are seemingly ubiquitous - members include proteins of eukaryotic, bacterial and archaeal origin. RAD3 is involved in nucleotide excision repair, and forms part of the transcription factor TFIIH in yeast [1].

1: Nucleotide excision repair in yeast. Prakash S, Prakash L; Mutat Res 2000;451:13-24. PMID:10915862