Poly-γ-glutamate tails are a distinctive feature of folate and F420 cofactors, but it was unclear how these tails elongate while maintaining substrate specificity. Here, the authors discover that folylpolyglutamate synthase and γ-glutamyl ligase enzymes add successive L-glutamates to the termini of the growing γ-glutamyl chain in a processive mechanism.
- Ghader Bashiri
- Esther M. M. Bulloch
- Christopher J. Squire