Extended Data Fig. 5: A charge relay supports deprotonation of GG-DHB.
From: A monodomain class II terpene cyclase assembles complex isoprenoid scaffolds
The structure of MstE_D109N:GG-DHB reveals the formation of a triad between Glu339, Arg337 and Asp162. Asp162 forms a salt bridge with the guanidino group of Arg337. This pushes electrons towards the secondary amine which in turn polarizes the carboxylate of Glu339, strengthening the H-bond with the meta-hydroxy group of DHB and increasing basicity. After deprotonation, this cluster acts as a proton-relay, before it is promptly broken and reordered to accommodate the product. Heteroatoms are highlighted in red (O) and blue (N); the proton (light blue) was added with PyMol. Interactions are represented as dashed lines (distance given in Å).
