Cloning and Characterization of an Environmental DNA-Derived Gene Cluster That Encodes the Biosynthesis of the Antitumor Substance BE-54017

Laboratory of Genetically Encoded Small Molecules, The Rockefeller University, Howard Hughes Medical Institute, 1230 York Avenue, New York, New York 10065, USA.
Journal of the American Chemical Society (Impact Factor: 12.11). 05/2011; 133(26):9996-9. DOI: 10.1021/ja2022653
Source: PubMed


Soil is predicted to contain thousands of unique bacterial species per gram. Soil DNA libraries represent large reservoirs of biosynthetic diversity from which diverse secondary metabolite gene clusters can be recovered and studied. The screening of an archived soil DNA library using primers designed to target oxytryptophan dimerization genes allowed us to identify and functionally characterize the first indolotryptoline biosynthetic gene cluster. The recovery and heterologous expression of an environmental DNA-derived gene cluster encoding the biosynthesis of the antitumor substance BE-54017 is reported here. Transposon mutagenesis identified two monooxygenases, AbeX1 and AbeX2, as being responsible for the transformation of an indolocarbazole precursor into the indolotryptoline core of BE-54017.

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Available from: Fang-Yuan Chang, Dec 24, 2013
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    • "Additionally, soil DNA isolated from the Anza-Borrego Desert in California was used to select an indolotryptoline-base for a biosynthetic gene cluster, encoding borregomycins (Figure 2; Chang and Brady, 2013). A similar approach was also applied to an antitumor substance BE-54017, also from an indolotryptoline gene cluster (Chang and Brady, 2011). Borregomycins may be yielded from a branched tryptophan dimer biosynthetic "
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    • "The primer set has also been reported in other screening studies for talosins A and B cluster, an antifungal [54], for caprazamycin biosynthesis, an antimycobacterial [55], and more recently we have used this set to screen for amicetin biosynthesis gene cluster, an antibacterial and antiviral agent [56]. The second primer set was designed by Chang and Brady [30] who screened a previously archived soil eDNA cosmid library by PCR using degenerate primers designed to recognize conserved regions in known oxytryptophan dimerization genes (StaD/RebD/VioB etc). The oxytryptophan dimerization enzymes were chosen as probes because this enzyme family is used in the biosynthesis of structurally diverse tryptophan dimmers, which have shown an antitumoral activity. "
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