CLONING AND SEQUENCING OF AN ALPHA-GLUCOSIDASE GENE FROM ASPERGILLUS-NIGER AND ITS EXPRESSION IN ASPERGILLUS-NIDULANS

We have cloned an extracellular alpha-glucosidase gene from Aspergillu s niger with oligonucleotide probes synthesized on the basis of the de termined peptide sequences. The nucleotide sequence revealed an open r eading frame of 985 amino acids split with three introns, and the dedu ced amino acid sequence was nearly identical to that of the alpha-gluc osidase previously determined. The cloned gene was introduced into Asp ergillus nidulans, and its expression in the transformants was shown t o be regulated by the carbon sources in the medium, suggesting that a common regulatory expression system is shared by these two species as is the case of other starch-degrading enzymes of Aspergillus species. (C) 1997 Elsevier Science B.V.