Aspergillus fumigatus pathogenicity and competition for resources may be augmented by its numerous secondary metabolites. Secondary metabolite biosynthetic genes are typically organized in clusters containing most if not all of the structural enzyme genes required for product biosynthesis. The A. fumigatus genome contains 24 clusters with polyketide synthase, non-ribosomal peptide synthase or dimethylallyl tryptophan synthase genes which range in size from 20 kb to 60 kb and contain from 6 to 22 genes. These clusters are dispersed throughout the genome with only 8 of the 24 located in subtelomeric regions. Many A. fumigatus clusters contain regulatory genes, genes associated with resistance to the metabolite, and apparently unrelated genes with no obvious role in production of the metabolite in question. Twelve clusters contain genes encoding transcription factors involved in the regulation of polyketide production and other secondary metabolite biosynthetic pathways. W ith the availability of several other sequenced Aspergilli and related filamentous fungi, we have undertaken a comparative analysis of the secondary metabolite biosynthetic genes and clusters. Some A. fumigatus clusters have orthologs in Aspergillus nidulans or Aspergillus oryzae while most are A. fumigatus specific. W e will report on these and other comparative aspects of these clusters, including chromosomal localizations, cross-species cluster integrity, inter- and intra- species relatedness of paralogous genes and the likelihood of interspecific and perhaps interkingdom horizontal gene transfer.
Full conference title:
23rd Fungal Genetics Conference
- Fungal Genetics Conference 23rd (2002)