9KOV

Crystal structure of an amidohydrolase mutant from Thermonema

Summary for 9KOV

• Entry DOI: 10.2210/pdb9kov/pdb
• Descriptor: trum-mut, ZINC ION (3 entities in total)
• Functional Keywords: degradation, hydrolase
• Biological source: Pyrinomonas methylaliphatogenes
• Total number of polymer chains: 8
• Total formula weight: 360326.44

Authors

Xu, N.N.,Jian, G.,Wei, H.L.,Chen, Y.Y.,Wu, P.,Han, X.,Liu, W. (deposition date: 2024-11-21, release date: 2025-11-26)

Primary citation

Xu, N.,Yan, M.,Liang, X.,Qin, H.,Gao, J.,Liu, W.
A thermostable OTA-detoxifying hydrolase from Thermonema rossianum: identification, characterization, structure, catalytic mechanism, and application.
Food Chem, 485:144515-144515, 2025

PubMed Abstract: Ochratoxin A (OTA) is highly toxic and widely distributed, posing serious threats to human and animal health. Searching for effective OTA-detoxifying enzyme is crucial for the prevention and control of OTA contaminations. Here, a new OTA-detoxifying enzyme, TrADH from Thermonema rossianum is identified, which exhibits highest temperature tolerance among OTA-detoxifying enzymes. TrADH maintains good activity in the range of 45-85 °C and retains about 50 % activity after heating at 70 °C for 30 min. Based on the solved crystal structures, the catalytic mechanism is proposed, and protein engineering of catalytic-related residues is performed to obtain a 2.1-fold upgraded variant TrADHS67E with the specific enzyme activity of 3990 U/mg, which is more efficient than the reported OTA-detoxifying enzymes. The efficient degradation of OTA in rum and walnut reveals the prospect of TrADH in food applications. The results indicate that TrADH has the potential in OTA bio-detoxification in food and feed industry.

PubMed: 40318335
DOI: 10.1016/j.foodchem.2025.144515

Experimental method

X-RAY DIFFRACTION (2.56 Å)