Analysis of two Aspergillus nidulans genes encoding extracellular proteases

Characterization of prtA Delta mutants, generated by gene disruption, showe d that the prfA gene is responsible for the majority of extracellular prote ase activity secreted by Aspergillus nidulans at both neutral and acid pH, The prtA Delta mutation was used to map the prtA gene to chromosome V, Thou gh aspartic protease activity has never been reported in A, nidulans and th e prtA Delta mutants appear to lack detectable acid protease activity, a ge ne (prtB) encoding a putative aspartic protease was isolated from this spec ies. Comparison of the deduced amino acid sequence of PrtB to the sequence of other aspergillopepsins suggests that the putative prtB gene product con tains an eight-amino-acid deletion prior to the second active site Asp resi due of the protease, RT-PCR experiments showed that the prtB gene is expres sed, albeit at a low level. (C) 2000 Academic Press.