Four distinct laccase genes,lcc1, lcc2, lcc3 andlcc4, have been identified in the fungusRhizoctonia solani. Both cDNA and genomic copies of these genes were isolated and characterized. Hybridization analyses indicate that each of the four laccase genes is present in a single copy in the genome. TheR. solani laccases can be divided into two groups based on their protein size, intron/exon organization, and transcriptional regulation. Three of these enzymes have been expressed in the fungusAspergillus oryzae. Two of the recombinant laccases, r-lccl and r-lcc4, as well as the native lcc4 enzyme were purified and characterized. The purified proteins are homodimeric, comprised of two subunits of approximately 66 kDa for lcc4 and 50–100 kDa for the recombinant lccl protein. These laccases have spectral properties that are consistent with other blue copper proteins. With syringaldazine as a substrate, lcc4 has optimal activity at pH 7, whereas lcc1 has optimal activity at pH 6.