7VQ6

Structure of a specialized glyoxalase from Gossypium hirsutum

Summary for 7VQ6

• Entry DOI: 10.2210/pdb7vq6/pdb
• Descriptor: Lactoylglutathione lyase, NICKEL (II) ION (3 entities in total)
• Functional Keywords: glyoxalase, lyase
• Biological source: Gossypium hirsutum (Upland cotton, Gossypium mexicanum)
• Total number of polymer chains: 2
• Total formula weight: 42703.50

Authors

Li, H.,Hu, Y.M.,Dai, L.H.,Chen, C.C.,Huang, J.W.,Liu, W.D.,Guo, R.T. (deposition date: 2021-10-19, release date: 2022-07-27, Last modification date: 2023-11-29)

Primary citation

Hu, Y.,Li, H.,Min, J.,Yu, Y.,Liu, W.,Huang, J.W.,Zhang, L.,Yang, Y.,Dai, L.,Chen, C.C.,Guo, R.T.
Crystal structure and biochemical analysis of the specialized deoxynivalenol-detoxifying glyoxalase SPG from Gossypium hirsutum.
Int.J.Biol.Macromol., 200:388-396, 2022

PubMed Abstract: Deoxynivalenol (DON) and its acetylated derivatives such as 3-acetyldeoxynivalenol (3A-DON) and 15-acetyldeoxynivalenol (15A-DON) are notorious mycotoxins in Fusarium contaminated cereals, which pose a great threat to human and livestock health. The specialized glyoxalase I from Gossypium hirsutum (SPG) can lower the toxicity of 3A-DON by conducting isomerization to transfer C8 carbonyl to C7 and double bond from C9-C10 to C8-C9. Here we report that the substrate-flexible SPG can also recognize 15A-DON and DON, probably following the same isomerization mechanism as that for 3A-DON. The crystallographic, mutagenesis, and biochemical analyses revealed that SPG provides a hydrophobic pocket to accommodate the substrate and residue E167 might serve as the catalytic base. A variant SPG that was constructed based on structure-based protein engineering exhibited elevated catalytic activity towards DON, 3A-DON, and 15A-DON by >70%. Furthermore, variant SPG was successfully expressed in Pichia pastoris, whose catalytic activity was also compared to that produced in Escherichia coli. These results provide a blueprint for further protein engineering of SPG and reveal the potential applications of the enzyme in detoxifying DON, 3A-DON and 15A-DON.

PubMed: 35051496
DOI: 10.1016/j.ijbiomac.2022.01.055

Experimental method

X-RAY DIFFRACTION (1.39 Å)