We have investigated four distinct sequences in genomic DNA of Phanerochaete chrysosporium that show strong homology to a lignin peroxidase cDNA sequence [Tien and Tu: Nature 236 (1987) 520-523, and 328 (1987) 742]. The complete nucleotide sequence of one of these genes is presented here. Comparison of the sequenced gene, LIG1, with the published cDNA sequence reveals the presence of eight short intervening sequences. The open reading frame encodes a polypeptide of 372 amino acids (aa), which includes a 28-aa residue hydrophobic leader sequence. The predicted Mr of the mature protein product is 37,000. Partial sequencing of the other three genes reveals substantial nucleotide and amino acid homology.