@article{BaunachChowdhuryStallforthetal.2021, author = {Baunach, Martin and Chowdhury, Somak and Stallforth, Pierre and Dittmann-Th{\"u}nemann, Elke}, title = {The landscape of recombination events that create nonribosomal peptide diversity}, series = {Molecular biology and evolution : MBE}, volume = {38}, journal = {Molecular biology and evolution : MBE}, number = {5}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0737-4038}, doi = {10.1093/molbev/msab015}, pages = {2116 -- 2130}, year = {2021}, abstract = {Nonribosomal peptides (NRP) are crucial molecular mediators in microbial ecology and provide indispensable drugs. Nevertheless, the evolution of the flexible biosynthetic machineries that correlates with the stunning structural diversity of NRPs is poorly understood. Here, we show that recombination is a key driver in the evolution of bacterial NRP synthetase (NRPS) genes across distant bacterial phyla, which has guided structural diversification in a plethora of NRP families by extensive mixing andmatching of biosynthesis genes. The systematic dissection of a large number of individual recombination events did not only unveil a striking plurality in the nature and origin of the exchange units but allowed the deduction of overarching principles that enable the efficient exchange of adenylation (A) domain substrates while keeping the functionality of the dynamic multienzyme complexes. In the majority of cases, recombination events have targeted variable portions of the A(core) domains, yet domain interfaces and the flexible A(sub) domain remained untapped. Our results strongly contradict the widespread assumption that adenylation and condensation (C) domains coevolve and significantly challenge the attributed role of C domains as stringent selectivity filter during NRP synthesis. Moreover, they teach valuable lessons on the choice of natural exchange units in the evolution of NRPS diversity, which may guide future engineering approaches.}, language = {en} } @article{SoeriyadiOngleyKehretal.2021, author = {Soeriyadi, Angela H. and Ongley, Sarah E. and Kehr, Jan-Christoph and Pickford, Russel and Dittmann, Elke and Neilan, Brett A.}, title = {Tailoring enzyme stringency masks the multispecificity of a lyngbyatoxin (indolactam alkaloid) nonribosomal peptide synthetase}, series = {ChemBioChem}, volume = {23}, journal = {ChemBioChem}, number = {3}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1439-4227}, doi = {10.1002/cbic.202100574}, pages = {6}, year = {2021}, abstract = {Indolactam alkaloids are activators of protein kinase C (PKC) and are of pharmacological interest for the treatment of pathologies involving PKC dysregulation. The marine cyanobacterial nonribosomal peptide synthetase (NRPS) pathway for lyngbyatoxin biosynthesis, which we previously expressed in E. coli, was studied for its amenability towards the biosynthesis of indolactam variants. Modification of culture conditions for our E. coli heterologous expression host and analysis of pathway products suggested the native lyngbyatoxin pathway NRPS does possess a degree of relaxed specificity. Site-directed mutagenesis of two positions within the adenylation domain (A-domain) substrate-binding pocket was performed, resulting in an alteration of substrate preference between valine, isoleucine, and leucine. We observed relative congruence of in vitro substrate activation by the LtxA NRPS to in vivo product formation. While there was a preference for isoleucine over leucine, the substitution of alternative tailoring domains may unveil the true in vivo effects of the mutations introduced herein.}, language = {en} } @misc{KehrPicchiDittmannThuenemann2011, author = {Kehr, Jan-Christoph and Picchi, Douglas Gatte and Dittmann-Th{\"u}nemann, Elke}, title = {Natural product biosyntheses in cyanobacteria a treasure trove of unique enzymes}, series = {Beilstein journal of organic chemistry}, volume = {7}, journal = {Beilstein journal of organic chemistry}, number = {2}, publisher = {Beilstein-Institut zur F{\"o}rderung der Chemischen Wissenschaften}, address = {Frankfurt, Main}, issn = {1860-5397}, doi = {10.3762/bjoc.7.191}, pages = {1622 -- 1635}, year = {2011}, abstract = {Cyanobacteria are prolific producers of natural products. Investigations into the biochemistry responsible for the formation of these compounds have revealed fascinating mechanisms that are not, or only rarely, found in other microorganisms. In this article, we survey the biosynthetic pathways of cyanobacteria isolated from freshwater, marine and terrestrial habitats. We especially emphasize modular nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) pathways and highlight the unique enzyme mechanisms that were elucidated or can be anticipated for the individual products. We further include ribosomal natural products and UV-absorbing pigments from cyanobacteria. Mechanistic insights obtained from the biochemical studies of cyanobacterial pathways can inspire the development of concepts for the design of bioactive compounds by synthetic-biology approaches in the future.}, language = {en} } @article{ReynaGonzalezSchmidPetrasetal.2016, author = {Reyna-Gonz{\´a}lez, Emmanuel and Schmid, Bianca and Petras, Daniel and S{\"u}ssmuth, Roderich D. and Dittmann, Elke}, title = {Leader Peptide-Free In Vitro Reconstitution of Microviridin Biosynthesis Enables Design of Synthetic Protease-Targeted Libraries}, series = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, volume = {55}, journal = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1433-7851}, doi = {10.1002/anie.201604345}, pages = {9398 -- 9401}, year = {2016}, abstract = {Microviridins are a family of ribosomally synthesized and post-translationally modified peptides with a highly unusual architecture featuring non-canonical lactone as well as lactam rings. Individual variants specifically inhibit different types of serine proteases. Here we have established an efficient in vitro reconstitution approach based on two ATP-grasp ligases that were constitutively activated using covalently attached leader peptides and a GNAT-type N-acetyltransferase. The method facilitates the efficient in vitro one-pot transformation of microviridin core peptides to mature microviridins. The engineering potential of the chemo-enzymatic technology was demonstrated for two synthetic peptide libraries that were used to screen and optimize microviridin variants targeting the serine proteases trypsin and subtilisin. Successive analysis of intermediates revealed distinct structure-activity relationships for respective target proteases.}, language = {en} } @article{SchmidtKunz2013, author = {Schmidt, Bernd and Kunz, Oliver}, title = {Bidirectional cross metathesis and ring-closing metathesis/ring opening of a C-2-symmetric building block: a strategy for the synthesis of decanolide natural products}, series = {Beilstein journal of organic chemistry}, volume = {9}, journal = {Beilstein journal of organic chemistry}, publisher = {Beilstein-Institut zur F{\"o}rderung der Chemischen Wissenschaften}, address = {Frankfurt, Main}, issn = {1860-5397}, doi = {10.3762/bjoc.9.289}, pages = {2544 -- 2555}, year = {2013}, abstract = {Starting from the conveniently available ex-chiral pool building block (R,R)-hexa-1,5-diene-3,4-diol, the ten-membered ring lactones stagonolide E and curvulide A were synthesized using a bidirectional olefin-metathesis functionalization of the terminal double bonds. Key steps are (i) a site-selective cross metathesis, (ii) a highly diastereoselective extended tethered RCM to furnish a (Z,E)-configured dienyl carboxylic acid and (iii) a Ru-lipase-catalyzed dynamic kinetic resolution to establish the desired configuration at C9. Ring closure was accomplished by macrolactonization. Curvulide A was synthesized from stagonolide E through Sharpless epoxidation.}, language = {en} }