6533b861fe1ef96bd12c56f7
RESEARCH PRODUCT
Potential active-site residues in polyneuridine aldehyde esterase, a central enzyme of indole alkaloid biosynthesis, by modelling and site-directed mutagenesis
Xueyan MaJoachim StöckigtEmine Mattern-dogruJoachim HartmannHeinz Deckersubject
chemistry.chemical_classificationHydroxynitrile lyasebiologyStereochemistryMutagenesisActive siteBiochemistryPolyneuridine-aldehyde esteraseEnzymechemistryBiochemistryHydrolaseCatalytic triadbiology.proteinSite-directed mutagenesisdescription
In the biosynthesis of the antiarrhythmic alkaloid ajmaline, polyneuridine aldehyde esterase (PNAE) catalyses a central reaction by transforming polyneuridine aldehyde into epi-vellosimine, which is the immediate precursor for the synthesis of the ajmalane skeleton. The PNAE cDNA was previously heterologously expressed in E. coli. Sequence alignments indicated that PNAE has a 43% identity to a hydroxynitrile lyase from Hevea brasiliensis, which is a member of the α/β hydrolase superfamily. The catalytic triad, which is typical for this family, is conserved. By site-directed mutagenesis, the members of the catalytic triad were identified. For further detection of the active residues, a model of PNAE was constructed based on the X-ray crystallographic structure of hydroxynitrile lyase. The potential active site residues were selected on this model, and were mutated in order to better understand the relationship of PNAE with the α/β hydrolases, and as well its mechanism of action. The results showed that PNAE is a novel member of the α/β hydrolase enzyme superfamily.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2002-06-01 | European Journal of Biochemistry |