This domain is found in uncharacterised proteins from bacteria, archaea and eukaryotes, including NTF2-Like SgcJ protein from Streptomyces carzinostaticus, which plays a role in the biosynthesis of the 9-membered enediyne antitumor antibiotic C-1027. It shows a cone-like alpha+beta barrel structure with a long N-terminal alpha- helix, a curved six-stranded antiparallel beta-sheet and two additional shorter alpha-helices. Its specific function is still unkown [1].

1: Crystal structure of SgcJ, an NTF2-like superfamily protein involved in biosynthesis of the nine-membered enediyne antitumor antibiotic C-1027. Huang T, Chang CY, Lohman JR, Rudolf JD, Kim Y, Chang C, Yang D, Ma M, Yan X, Crnovcic I, Bigelow L, Clancy S, Bingman CA, Yennamalli RM, Babnigg G, Joachimiak A, Phillips GN, Shen B; J Antibiot (Tokyo). 2016;69:731-740. PMID:27406907