7XWI

structure of patulin-detoxifying enzyme with NADPH

Summary for 7XWI

• Entry DOI: 10.2210/pdb7xwi/pdb
• Descriptor: Short-chain dehydrogenase/reductase, NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE (3 entities in total)
• Functional Keywords: dehydrogenases/reductase, oxidoreductase
• Biological source: Meyerozyma guilliermondii
• Total number of polymer chains: 4
• Total formula weight: 115264.81

Authors

Dai, L.,Li, H.,Hu, Y.,Guo, R.T.,Chen, C.C. (deposition date: 2022-05-26, release date: 2022-10-26, Last modification date: 2024-05-08)

Primary citation

Dai, L.,Li, H.,Huang, J.W.,Hu, Y.,He, M.,Yang, Y.,Min, J.,Guo, R.T.,Chen, C.C.
Structure-based rational design of a short-chain dehydrogenase/reductase for improving activity toward mycotoxin patulin.
Int.J.Biol.Macromol., 222:421-428, 2022

PubMed Abstract: Patulin is a fatal mycotoxin that is widely detected in drinking water and fruit-derived products contaminated by diverse filamentous fungi. CgSDR from Candida guilliermondii represents the first NADPH-dependent short-chain dehydrogenase/reductase that catalyzes the reduction of patulin to the nontoxic E-ascladiol. To elucidate the catalytic mechanism of CgSDR, we solved its crystal structure in complex with cofactor and substrate. Structural analyses indicate that patulin is situated in a hydrophobic pocket adjacent to the cofactor, with the hemiacetal ring orienting toward the nicotinamide moiety of NADPH. In addition, we conducted structure-guided engineering to modify substrate-binding residue V187 and obtained variant V187F, V187K and V187W, whose catalytic activity was elevated by 3.9-, 2.2- and 1.7-fold, respectively. The crystal structures of CgSDR variants suggest that introducing additional aromatic stacking or hydrogen-bonding interactions to bind the lactone ring of patulin might account for the observed enhanced activity. These results illustrate the catalytic mechanism of SDR-mediated patulin detoxification for the first time and provide the upgraded variants that exhibit tremendous potentials in industrial applications.

PubMed: 36176222
DOI: 10.1016/j.ijbiomac.2022.09.121

Experimental method

X-RAY DIFFRACTION (2.22 Å)