Regulation of Acetamide Catabolism

Abstract

The amdS gene of Aspergillus nidulans encodes an acetamidase enzyme that hydrolyzes acetamide and a limited range of other amides. This allows acetamide to be used as a sole source of nitrogen or as a source of carbon. As far as we know, the function of this gene is of no great intrinsic interest with respect to the physiology or development of A. nidulans. Deletion mutants of amdS have no detectable phenotype other than an inability to catabolize acetamide (Hynes 1979). It should also be noted that acetamide is a very poor sole source of carbon or nitrogen, and is unlikely to be a significant source of metabolites in the natural environment. However, the study of the amdS gene and its regulation has provided much information regarding mechanisms of gene regulation in fungi, as well as insights into how catabolic pathways are coordinated. Furthermore, the amdS gene has been of considerable importance in the development of fungal transformation systems (Tilburn et al. 1983; Kelly and Hynes 1985; Fincham 1989). In this chapter we discuss in detail the genetical and molecular analysis of the amdS gene and how this has contributed to the field of fungal molecular genetics.