We have cloned and sequenced genomic DNA of Aspergillus oryzae palB(ory), orthologue of Emericella nidulans palB, which encodes a calpain-like protease modulating a signal transduction pathway during alkaline adaptation. The deduced amino acid sequence of PalB(ory) is 70.0% identical to PalB over its entire length. The regions with high similarity revealed possible domains important for their function. This is the first step towards understanding the alkaline adaptation mechanism of A. oryzae, which would be very useful in the fermentation industry.