The diphenol oxidase gene (DP01) from Cryptococcus neoformans has been cloned on a 2.4 kb fragment and the sequence determined from been both cDNA and genomic DNA. The genomic sequence contains 14 introns, the longest of which contain 450 bases. DP01 codes for 75 amino acids which have a sequence identity with the copper binding sites of various laccases, ascorbate oxidase and ceruloplasm. The purified enzyme is a 66 kDa glycoprotein which has the ability to oxidize dopamine to dopachrome (identified by HPLC-mass spectroscopy), the first intermediate during melanin synthesis. The protein appears to have several novel features for enzymes of its class including an unusual absorbance at 420 nm. Three surface proteins from Cryptococcus neoformans have been isolated, one of which may be secreted serine protease. These proteins are of interest as potential vaccine targets and for their role in capsular polysaccharide biosynthesis.
