Crystal structures of 40- and 71-substitution variants of hydroxynitrile lyase from rubber tree.

ABSTRACT: Hydroxynitrile lyase from Hevea brasiliensis (HbHNL) and the esterase SABP2 from Nicotiana tabacum share the α/β-hydrolase fold, a Ser-His-Asp catalytic triad and 44% sequence identity, yet catalyze different reactions. Prior studies showed that three active-site substitutions in HbHNL conferred weak esterase activity. To investigate how regions beyond the active site influence catalytic efficiency and active-site geometry, we engineered HbHNL variants with increasing numbers of substitutions to match SABP2. Variant HNL16 has all amino acids within 6.5 Å of the active site identical to SABP2, HNL40 those within 10 Å and HNL71 those within 14 Å. HNL16 exhibited poor esterase activity, whereas both HNL40 and HNL71 showed efficient esterase catalysis, demonstrating that residues beyond the im

SUBMITTER: Pierce CT 

PROVIDER: S-EPMC12400190 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature