Characterization of the oat1 gene of Penicillium chrysogenum encoding an ω-aminotransferase: induction by L-lysine, L-ornithine and L-arginine and repression by ammonium
- Authors
- Type
- Published Article
- Journal
- Molecular Genetics and Genomics
- Publisher
- Springer-Verlag
- Publication Date
- Sep 15, 2005
- Volume
- 274
- Issue
- 3
- Pages
- 283–294
- Identifiers
- DOI: 10.1007/s00438-005-0019-2
- Source
- Springer Nature
- Keywords
- License
- Yellow
Abstract
The Penicillium chrysogenumoat1 gene, which encodes a class III ω-aminotransferase, was cloned and characterized. This enzyme converts lysine into 2-aminoadipic semialdehyde, and plays an important role in the biosynthesis of 2-aminoadipic acid, a precursor of penicillin and other β-lactam antibiotics. The enzyme is related to ornithine-5-aminotransferases and to the lysine-6-aminotransferases encoded by the lat genes found in bacterial cephamycin gene clusters. Expression of oat1 is induced by lysine, ornithine and arginine, and repressed by ammonium ions. AreA-binding GATA and GATT sequences involved in regulation by ammonium, and an 8-bp direct repeat associated with arginine induction in Emericella (Aspergillus nidulans and Saccharomyces cerevisiae, were found in the oat1 promoter region. Deletion of the oat1 gene resulted in the loss of ω-aminotransferase activity. The null mutants were unable to grow on ornithine or arginine as sole nitrogen sources and showed reduced growth on lysine. Complementation of the null mutant with the oat1 gene restored normal levels of ω-aminotransferase activity and the ability to grow on ornithine, arginine and lysine. The role of the oat1 gene in the biosynthesis of 2-aminoadipic acid is discussed.
