The trpC gene of Phanerochaete chrysosporium is unique in containing an intron but nevertheless maintains the order of functional domains seen in other fungi.

The Phanerochaete chryososporium trpC gene has been isolated by complementation of an Escherichia coli trpC mutant. The full extent of the fungal gene, determined by sequence analysis, was found to be 2414bp. This includes a single intron of 50bp, the presence of which was confirmed by RNA-primed polymerase chain reaction analysis. This features makes the P. chrysosporium gene unique when compared to equivalent genes from other filamentous fungi. The P. chrysosporium trpC gene encodes a single protein containing three enzyme activities involved in tryptophan biosynthesis arranged in the order: NH2-GAT-IGPS-PRAI-COOH. This order is conserved in all filamentous fungi so far examined and, indeed, is the gene order within the E. coli trp operon.