Laccase is a copper-containing oxidase enzyme that is present in many microorganisms, plants, and fungi. It plays an important role in the biodegradation of lignin and is known as a lignin-modifying enzyme. Due to the irregular structure of lignin molecules, laccase can utilize a wide range of substrates, such as toxic substances and antibiotics. In this study, laccase from Streptomyces sp. CS29 was studied for properties including optimal pH and temperature, as well as its stability. The effects of some chemicals, metal ions, and organic solvents on laccase activity were also examined. We found that the tested metal ions had different effects on laccase activity. It was observed that 10 and 20 mM Ca2+, 20 mM Zn2+, and 10 mM K+ increased laccase activity, while 10 and 20 mM Fe2+ inhibited it. Laccase activity was also inhibited by 100 mM EDTA and urea but was activated by 50 and 100 mM SDS. Finally, 20% of organic solvents, including ethanol, ethyl acetate, DMSO, acetone, and methanol, decreased laccase activity. Additionally, the crude laccase was tested for sulfamethoxazole degradation. The optimal pH for sulfamethoxazole degradation was pH 3.0 with a 97.90% degradation rate. Furthermore, we used the three-dimensional structure of laccase, obtained from whole genome sequencing data, to investigate the molecular interactions between laccase and sulfamethoxazole. The results of the computational study supported the wet lab experiments in which sulfamethoxazole was degraded by laccase sufficiently. Overall, the results suggest that laccase from Streptomyces sp. CS29 has potential for utilization in bioremediation or environmental biotechnology applications. [ABSTRACT FROM AUTHOR]