“…Mutations within the RRE precluded the recognition of the corresponding precursor peptides (Burkhart et al, 2015), thus validating RREs as a general scaffold needed for precursor peptide recognition during RiPP biosynthesis. Mutational studies using the sactipeptide RiPP biosynthetic machinery has also been performed, revealing the importance of the RRE for sactipeptide maturation (Wieckowski et al, 2015). Interestingly, the RRE domain sometimes may exist as a stand-alone protein and not as a subdomain within a RiPP biosynthetic enzyme as recently observed for lasso peptides and thiazole/oxazole-modified peptide gene clusters (Burkhart et al, 2015, Dunbar et al, 2015, Elsayed et al, 2015, Gavrish et al, 2014, Inokoshi et al, 2012, Li et al, 2015, Metelev et al, 2015).…”