Biosynthetic and mode of action studies on the nonribosomal peptide antibiotic hormaomycin

• Applicant: Professor Dr. Jörn Piel
• Subject Area: Biological and Biomimetic Chemistry ; Biochemistry
• Term: from 2008 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 33421847

• Final Report Year: 2019

Final Report Abstract

The project generated diverse insights into the biosynthesis and mode of action of hormaomycin, a narrow-spectrum antibiotic and regulator of bacterial development and metabolism. For the many unusual amino acid building blocks that comprise the hormaomycin structure, key biosynthetic enzymes and pathways were characterized, but some steps remain to be clarified. A complex regulatory mechanism was identified that governs not only overall hormaomycin production but also adjusts incorporation of individual building blocks. We showed that hormaomycin acts as metabolic inducer on a broad range of Streptomyces bacteria, which are important sources of bioactive natural products. Among the responsive bacteria, the model organisms Streptomyces coelicolor was identified, which provided opportunities to study the effects of hormaomycin at a global metabolic scale using mass spectrometric imaging and networking methods. This showed that for some biosynthetic pathways, hormaomycin accelerates and increases production, while in other cases cryptic natural products are activated that would not be observable by standard cultivation. This function suggests hormaomycin as useful tool in natural product discovery. To facilitate its use, we created a hormaomycin overproducer with a 135-fold production as compared to the wild-type organism. Insights into the cellular target of hormaomycin were provided by generating a modified hormaomycin analog in a combined synthetic-biosynthetic strategy. This analog contains an alkyne moiety that can be labeled, but is still active as antibiotic and metabolic inducer. By proteomic and complementary methods, we identified F-ATPase as likely target. Furthermore, various hormaomycin congeners were isolated from the wild-type and mutant producers, which revealed moieties important for bioactivity. In further collaborations with groups internal and external to FOR 854, work on other antibiotics was conducted. This includes identification of various antibiotics and/or biosynthetic pathways for elansolids, bacillaene, corallopyronine (with G. König), phenylnannolone (with G. König), and notably polytheonamides (with H.-G. Sahl). The latter compounds are extraordinarily complex peptides produced by a bacterial symbiont of a marine sponge. In the frame of FOR 854 the bioactivity of polytheonamides was investigated based on the similarity of its three-dimensional structure to that gramicidin-type antibiotics. These data contributed to a publication in "Science".

Publications

• (2010). Genome mining reveals trans-AT polyketide synthase directed antibiotic biosynthesis in the bacterial phylum Bacteroidetes. ChemBioChem. 18, 2506-2512
  Teta R, Gurgui M, Helfrich EJN, Künne S, Schneider A, Van Echten-Deckert G, Mangoni A, Piel J
  
• (2010). The final steps of bacillaene biosynthesis in Bacillus amyloliquefaciens FZB42: direct evidence for β,γ-dehydration by a trans-acyltransferase polyketide synthase. Angew. Chem. Int. Ed. Eng. 49, 1465-1467
  Moldenhauer J, Götz DC, Albert CR, Bischof SK, Schneider K, Süssmuth RD, Engeser M, Gross H, Bringmann G, Piel J
  
• (2011). Insights into the biosynthesis of hormaomycin, an exceptionally complex bacterial signaling metabolite. Chem. Biol. 18, 381-391
  Höfer I, Crüsemann M, Radzom M, Geers B, Flachshaar D, Cai X, Zeeck A, Piel J
  
• (2012). Metagenome mining reveals polytheonamides as modified ribosomal peptides. Science 338, 387-390
  Freeman MF, Gurgui C,Helf MJ, Morinaka BI, Uria AR, Oldham NJ, Sahl HG, Matsunaga S, Piel J
  
• (2012). Reciprocal cross talk between fatty acid and antibiotic biosynthesis in a nematode symbiont. Angew. Chem. Int. Ed. Eng. 51, 12086-12089
  Brachmann AO, Reimer D, Lorenzen W, Augusto Alonso E, Kopp Y, Piel J, Bode HB
  
• (2013). Evolution-guided engineering of nonribosomal peptide synthetase adenylation domains. Chem. Sci. 4, 1041-1045
  Crüsemann M, Kohlhaas C, Piel J
  
• (2013). Manipulation of regulatory genes reveals complexity and fidelity in hormaomycin biosynthesis. Chem. Biol. 20, 839-846
  Cai XF, Teta R, Kohlhaas C, Crüsemann M, Ueoka R, Mangoni A, Freeman MF, Piel J
  
• (2014). Biosynthesis of phenylnannolone A, a MDR reversal agent from the halotolerant myxobacterium Nannocystis pusilla B150. ChemBioChem, 15, 757-765
  Bouhired SM, Crüsemann M, Almeida C, Weber T, Piel J, Schäberle TF, König GM