Polychlorinated biphenyls (PCBs) are a group of persistent organic pollutants (POPs) widely existing in the environment. Arthrobacter sp. YC-RL1 is a biphenyl-degrading bacterium that shows metabolic versatility towards aromatic compounds. A 2-hydroxy-6-oxo-6-phenylhexa-2, 4-dienoate (HOPDA) hydrolase (BphD) gene involved in the biodegradation of biphenyl was cloned from strain YC-RL1 and heterologously expressed in Escherichia coli BL21 (DE3). The recombinant BphD(YC-RL1) was purified and characterized. BphD(YC-RL1) showed the highest activity at 45 degrees C and pH 7. It was stable under a wide range of temperature (20-50 degrees C). The enzyme had a K-m value of 0.14mM, K-cat of 11.61s(-1), and V-max of 0.027U/mg. Temperature dependence catalysis exhibited a biphasic Arrhenius Plot with a transition at 20 degrees C. BphD(YC-RL1) was inactivated by SDS, Tween 20, Tween 80, Trition X-100, DTT, CHAPS, NBS, PMSF, and DEPC, but insensitive to EDTA. Site-directed mutagenesis of the active-site residues revealed that the catalytic triad residues (Ser115, His275, and Asp247) of BphD(YC-RL1) were necessary for its activity. The investigation of BphD(YC-RL1) not only provides new potential enzyme resource for the biodegradation of biphenyl but also helps deepen our understanding on the catalytic process and mechanism.