Members of this protein family are radical SAM enzymes proposed to act on small, Cys-rich peptides encoded by tandem gene pairs. Members occur in enzymes Fibrobacter succinogenes subsp. succinogenes S85 (genes for their target peptides missed) and in Ruminococcus albus 8. This enzyme family is similar in sequence to the SCIFF (Six Cysteines in Forty-Five) system maturase (TIGR03974).
Jiyao W et al.(2023). "The conserved domain database in 2023.",