A bacterial strain P2 capable of degrading 3, 5, 6-trichloro-2-pyridinol (TCP) was isolated and characterized.Based on morphological, physiological, biochemical characters, and phylogenetic analysis, strain P2 was identified as Cupriavidus pauculus.R could use TCP as the sole carbon source and energy source for growth.It showed a high average degradation rate of 10 mg/L.h in mineral salt medium amended with TCP (50-800 mg/L).Dehalogenation is an important mechanism for degrading and detoxifying halogenated aromatics in microbes.However, the biochemical and molecular mechanisms of dehalogenation of 3,5,6-trichloro-2-pyridinol (TCP) are still unknown.In this study, a novel 6012 bp gene cluster responsible for the dehalogenation of TCP was cloned from strain P2.The cluster included a monooxygenase gene (tcpA1), a flavin reductase gene (tcpB1), tcpR1, orfl and orf2.TcpA1 and TcpB1 were indispensable for the dehalogenation of TCP.They worked together to catalyze the dehalogenation of three chlorine of TCP, and generated a more readily biodegradable product of 3,6-dihydroxypyridine-2,5-dione.TcpA1 displayed the highest activity against TCP at 40 ℃ and at pH 8.0.Cu2+, Zn2+, and Hg2+ significantly inhibited enzyme activity.To the best of our knowledge, this is the first report on a gene cluster responsible for TCP degradation.