Submitted to: Biochemistry and Molecular Biology Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2015
Publication Date: 5/12/2015
Citation: Gold, S.E., Glenn, A.E. 2015. It’s War Out There: Fighting for life with xenobiotic degrading enzymes. Biochemistry and Molecular Biology Abstracts. Irapuato, Mexico, May 12-14, 2015
Technical Abstract: It’s War Out There: Fighting for life with xenobiotic degrading enzymes Beta-lactamase enzymes are well studied because of their tremendous impact on medicine. Their prominent role is in resistance to beta-lactam (four membered lactam ring) antibiotics including the first and most famous fungally derived medically important antibiotic, penicillin. These antibiotics primarily function by interfering with bacterial cell wall construction. Fungi also have genes that encode canonical beta-lactamase domains. Very little is known about the function of these enzymes in fungi. Clearly, they do not act to protect the fungus from beta-lactams since fungi have completely different walls and tend to be unaffected by these drugs. Two reports describe the functions of beta-lactamase genes in fungi, one functioning in the synthesis of a secondary metabolite and the other involved in breakdown of a plant xenobiotic. Fusarium species tend to possess large families of beta-lactamase encoding genes. In our fungus of interest, the fumonisin producer F. verticillioides, there are 46 beta-lactamase genes. Earlier we showed that one enzyme, encoded by FDB1-ORF5 (FVEG_08291), was responsible for detoxification of the maize benzoxazinone phytoanticipins, including BOA. BOA is a gamma-lactam, with a five membered lactam ring, and is cleaved by this enzyme. We are deep into a family-wide gene deletion project to determine the function of these enzymes, with the hypothesis that they are involved in chemical warfare with antagonistic organisms and that their expansion in the genus Fusarium is a driving force for the ubiquitous nature of F. verticillioides in agricultural soils.