Sulfate assimilation in Aspergillus terreus: analysis of genes encoding ATP-sulfurylase and PAPS-reductase.

Two genes for the sulfate assimilation pathway in Aspergillus terreus were cloned. The genes sAT (coding for PAPS-reductase) and sCT (coding for ATP-sulfurylase) form a small gene cluster. Both genes are similar to their homologs in A. nidulans (sA and sC), Penicillium chrysogenum (aps) and Saccharomyces cerevisiae (MET3 and MET16). In the coding sequence of the sCT gene, a typical non-functional APS-kinase-like domain is present. The sCT gene is expressed in A. nidulans, but its expression there is less sensitive to methionine level than in the original species. Two regions 5' upstream of sAT were found to be similar to those of sA.