Open AccessReduced Function of a Phenylacetate-Oxidizing Cytochrome P450 Caused Strong Genetic Improvement in Early Phylogeny of Penicillin-Producing Strains
Author(s) -
Marta RodríguezSáiz,
José Luis Barredo,
M. Moreno,
José Manuel Fernández-Cañón,
Miguel Peñalva,
Bruno Dı́ez
Publication year - 2001
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.183.19.5465-5471.2001
Subject(s) - phenylacetate , biology , aspergillus nidulans , penicillium chrysogenum , biochemistry , cytochrome p450 , mutant , mutation , gene , genetics , microbiology and biotechnology , metabolism
The single-copy pahA gene from Penicillium chrysogenum encodes a phenylacetate 2-hydroxylase that catalyzes the first step of phenylacetate catabolism, an oxidative route that decreases the precursor availability for penicillin G biosynthesis. PahA protein is homologous to cytochrome P450 monooxygenases involved in the detoxification of xenobiotic compounds, with 84% identity to the Aspergillus nidulans homologue PhacA. Expression level of pahA displays an inverse correlation with the penicillin productivity of the strain and is subject to induction by phenylacetic acid. Gene expression studies have revealed a reduced oxidative activity of the protein encoded by pahA genes from penicillin-overproducing strains of P. chrysogenum compared to the activity conferred by phacA of A. nidulans. Sequencing and expression of wild-type pahA from P. chrysogenum NRRL 1951 revealed that an L181F mutation was responsible for the reduced function in present industrial strains. The mutation has been tracked down to Wisconsin 49-133, a mutant obtained at the Department of Botany of the University of Wisconsin in 1949, at the beginning of the development of the Wisconsin family of strains.