CDNA CLONING, EXPRESSION, AND MUTAGENESIS OF SCYTALONE DEHYDRATASE NEEDED FOR PATHOGENICITY OF THE RICE BLAST FUNGUS, PYRICULARIA-ORYZAE

We purified seytalone dehydratase from the rice blast fungus. Pyricula ria oryzae, and cloned its cDNA on the basis of its amino acid sequenc e. The deduced amino acid sequence was 62% identical to the scytalone dehydratase from Colletotrichum lagenarium. The expression of this gen e was induced transcriptionally in the stationary phase when melanin s ynthesis occurs. We constructed a heterologous expression system for t he enzyme in Escherichia coli, did deletion analysis with this system, and found that a C-terminal region is essential for the enzyme functi on.