Substituting the catalytic proline of 4-oxalocrotonate tautomerase with non-canonical analogues reveals a finely tuned catalytic system.
Lukesch, M.S., Pavkov-Keller, T., Gruber, K., Zangger, K., Wiltschi, B.(2019) Sci Rep 9: 2697-2697
- PubMed: 30804446 
- DOI: https://doi.org/10.1038/s41598-019-39484-9
- Primary Citation of Related Structures:  
6GHW - PubMed Abstract: 
The enzyme 4-oxalocrotonate tautomerase shows remarkable catalytic versatility due to the secondary amine of its N-terminal proline moiety. In this work, we incorporated a range of proline analogues into the enzyme and examined the effects on structure and activity. While the structure of the enzyme remained unperturbed, its promiscuous Michael-type activity was severely affected. This finding demonstrates how atomic changes in a biocatalytic system can abolish its activity. Our work provides a toolbox for successful generation of enzyme variants with non-canonical catalytic proline analogues.
Organizational Affiliation: 
Graz University of Technology, Institute of Molecular Biotechnology, Petersgasse 14, 8010, Graz, Austria.