Redesigning Aldolase Stereoselectivity by Homologous Grafting

PLoS One. 2016 Jun 21;11(6):e0156525. doi: 10.1371/journal.pone.0156525. eCollection 2016.

Abstract

The 2-deoxy-d-ribose-5-phosphate aldolase (DERA) offers access to highly desirable building blocks for organic synthesis by catalyzing a stereoselective C-C bond formation between acetaldehyde and certain electrophilic aldehydes. DERA´s potential is particularly highlighted by the ability to catalyze sequential, highly enantioselective aldol reactions. However, its synthetic use is limited by the absence of an enantiocomplementary enzyme. Here, we introduce the concept of homologous grafting to identify stereoselectivity-determining amino acid positions in DERA. We identified such positions by structural analysis of the homologous aldolases 2-keto-3-deoxy-6-phosphogluconate aldolase (KDPG) and the enantiocomplementary enzyme 2-keto-3-deoxy-6-phosphogalactonate aldolase (KDPGal). Mutation of these positions led to a slightly inversed enantiopreference of both aldolases to the same extent. By transferring these sequence motifs onto DERA we achieved the intended change in enantioselectivity.

MeSH terms

  • Aldehyde-Lyases / chemistry
  • Aldehyde-Lyases / metabolism
  • Amino Acid Sequence
  • Amino Acids / metabolism
  • Biocatalysis
  • Escherichia coli / enzymology
  • Fructose-Bisphosphate Aldolase / chemistry
  • Fructose-Bisphosphate Aldolase / metabolism*
  • Kinetics
  • Models, Molecular
  • Phylogeny
  • Protein Engineering*
  • Protein Structure, Secondary
  • Pyruvates / metabolism
  • Stereoisomerism
  • Substrate Specificity

Substances

  • Amino Acids
  • Pyruvates
  • Aldehyde-Lyases
  • Fructose-Bisphosphate Aldolase
  • phospho-2-keto-3-deoxy-gluconate aldolase

Grants and funding

The authors gratefully acknowledge the Ministry of Innovation, Science and Research of the German federal state of North Rhine-Westphalia (NRW) and the Heinrich Heine University Düsseldorf (HHU; scholarship within the CLIB-Graduate Cluster Industrial Biotechnology for I.K., the NRW-Forschungsschule BioStruct for C.B. and T.C.), the Deutsche Forschungsgemeinschaft, and the Forschungszentrum Jülich GmbH for the support of the authors’ projects.