5T13

Structure of the Cyanuric Acid Hydrolase TrzD Reveals Product Exit Channel

Summary for 5T13

• Entry DOI: 10.2210/pdb5t13/pdb
• Descriptor: Cyanuric acid amidohydrolase, CARBON DIOXIDE, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: trzd - cyanuric acid hydrolase from acidovorax citrulli, atzd - cyanuric acid hydrolase from pseudomonas sp adp, acah - cyanuric acid hydrolase from azorhizobium calindulans., hydrolase
• Biological source: Enterobacter cloacae
• Total number of polymer chains: 1
• Total formula weight: 40404.67

Authors

Bera, A.K.,Wackett, L.P. (deposition date: 2016-08-17, release date: 2017-04-12, Last modification date: 2023-10-04)

Primary citation

Bera, A.K.,Aukema, K.G.,Elias, M.,Wackett, L.P.
Structure of the Cyanuric Acid Hydrolase TrzD Reveals Product Exit Channel.
Sci Rep, 7:45277-45277, 2017

PubMed Abstract: Cyanuric acid hydrolases are of industrial importance because of their use in aquatic recreational facilities to remove cyanuric acid, a stabilizer for the chlorine. Degradation of excess cyanuric acid is necessary to maintain chlorine disinfection in the waters. Cyanuric acid hydrolase opens the cyanuric acid ring hydrolytically and subsequent decarboxylation produces carbon dioxide and biuret. In the present study, we report the X-ray structure of TrzD, a cyanuric acid hydrolase from Acidovorax citrulli. The crystal structure at 2.19 Å resolution shows a large displacement of the catalytic lysine (Lys163) in domain 2 away from the active site core, whereas the two other active site lysines from the two other domains are not able to move. The lysine displacement is proposed here to open up a channel for product release. Consistent with that, the structure also showed two molecules of the co-product, carbon dioxide, one in the active site and another trapped in the proposed exit channel. Previous data indicated that the domain 2 lysine residue plays a role in activating an adjacent serine residue carrying out nucleophilic attack, opening the cyanuric acid ring, and the mobile lysine guides products through the exit channel.

PubMed: 28345631
DOI: 10.1038/srep45277

Experimental method

X-RAY DIFFRACTION (2.19 Å)