Epoxide hydrolysis as a model system for understanding flux through a branched reaction scheme

Janfalk Carlsson, Å.; Bauer, P.; Dobritzsch, D.; Kamerlin, S.C.L.; Widersten, M.

doi:10.1107/S2052252518003573

Figure 4
Structures of the enzyme variants analyzed in this work. (a) Superposition of the C^α traces of wild-type StEH1 (wheat) and the variants R-C1 (lime green), R-C1B1 (violet), R-C1B1D33 (aquamarine) and R-C1B1D33E6 (orange). (b) Overlay of active-site residues, including those that differ between the different enzyme variants. The catalytic residues are Asp105 (nucleophile), His300 (general base), Asp265 (charge relay) and Tyr154 and Tyr235 (acids) (see Fig. 1

for the full reaction mechanism). Glu35 and His104 are auxiliary catalytic residues. The hydrolytic water (wat) is also shown. A glycerol molecule (gol) bound in the active site of R-C1 has been included to show the substrate-binding pocket. The residue replacements are given in Table 2

. The modelled side-chain conformations of Lys141 should be considered arbitrary owing to a lack of clear electron density beyond C^γ. This figure was constructed from the atomic coordinates in PDB entries 2cjp (wild type; Mowbray et al., 2006