Submitted to: Handbook of Fungal Biotechnology
Publication Type: Review Article
Publication Acceptance Date: 9/1/2002
Publication Date: 1/1/2004
Citation: Cary, J.W. 2004. Secondary metabolic gene clusters in filamentous fungi. In: Arora, D.K., editor. Handbook of Fungal Biotechnology. Second Edition, Revised and Expanded. Marcel Dekker, Inc. p. 81-94.
Technical Abstract: Filamentous fungi produce a number of secondary metabolic compounds that have been shown to be both of great value (i.e. antibiotics and anti-hypercholesterolemics) and great harm (i.e. aflatoxins and trichothecenes). The genes responsible for producing the secondary metabolite are often clustered together on the chromosome. A number of fungal secondary metabolic gene clusters have been identified and characterized and, in general, these clusters share common genetic components with respect to function. In addition to the structural genes encoding the biosynthetic enzymes, the pathway cluster can also contain a gene(s) required for regulation of expression of the other pathway genes and a gene(s) required for export of the metabolite or "self protection" to the metabolite. A common question that inevitably arises during the study of fungal gene clusters has been why are the genes for these biosynthetic pathways maintained as a cluster(s) in the genome and what advantage does this impart on the fungus? In addition to discussing possible reasons for the existence and apparent maintenance of secondary metabolic gene clusters in fungi, this review provides key information and references on the molecular characterization of secondary metabolic pathways including (a) antibiotics, mycotoxins, etc. and (b) host-specific toxin biosynthetic pathways.