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Temporal and Fluoride Control of Secondary Metabolism Regulates Cellular Organofluorine Biosynthesis
journal contribution
posted on 2012-09-21, 00:00 authored by Mark C. Walker, Miao Wen, Amy M. Weeks, Michelle C. Y. ChangElucidating mechanisms of natural organofluorine biosynthesis
is
essential for a basic understanding of fluorine biochemistry in living
systems as well as for expanding biological methods for fluorine incorporation
into small molecules of interest. To meet this goal we have combined
massively parallel sequencing technologies, genetic knockout, and in vitro biochemical approaches to investigate the fluoride
response of the only known genetic host of an organofluorine-producing
pathway, Streptomyces cattleya. Interestingly, we
have discovered that the major mode of S. cattleya’s resistance to the fluorinated toxin it produces, fluoroacetate,
may be due to temporal control of production rather than the ability
of the host’s metabolic machinery to discriminate between fluorinated
and non-fluorinated molecules. Indeed, neither the acetate kinase/phosphotransacetylase
acetate assimilation pathway nor the TCA cycle enzymes (citrate synthase
and aconitase) exclude fluorinated substrates based on in
vitro biochemical characterization. Furthermore, disruption
of the fluoroacetate resistance gene encoding a fluoroacetyl-CoA thioesterase
(FlK) does not appear to lead to an observable growth defect related
to organofluorine production. By showing that a switch in central
metabolism can mediate and control molecular fluorine incorporation,
our findings reveal a new potential strategy toward diversifying simple
fluorinated building blocks into more complex products.