Applied and Environmental Microbiology 2002-09-01

Enzymatic degradation of chlorodiamino-s-triazine.

Jennifer L Seffernick, Nir Shapir, Michael Schoeb, Gilbert Johnson, Michael J Sadowsky, Lawrence P Wackett

Index: Appl. Environ. Microbiol. 68(9) , 4672-5, (2002)

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Abstract

2-Chloro-4,6-diamino-s-triazine (CAAT) is a metabolite of atrazine biodegradation in soils. Atrazine chlorohydrolase (AtzA) catalyzes the dechlorination of atrazine but is unreactive with CAAT. In this study, melamine deaminase (TriA), which is 98% identical to AtzA, catalyzed deamination of CAAT to produce 2-chloro-4-amino-6-hydroxy-s-triazine (CAOT). CAOT underwent dechlorination via hydroxyatrazine ethylaminohydrolase (AtzB) to yield ammelide. This represents a newly discovered dechlorination reaction for AtzB. Ammelide was subsequently hydrolyzed by N-isopropylammelide isopropylaminohydrolase to produce cyanuric acid, a compound metabolized by a variety of soil bacteria.