@article{MeyerMainzKehretal.2017, author = {Meyer, Sabine and Mainz, Andi and Kehr, Jan-Christoph and Suessmuth, Roderich and Dittmann, Elke}, title = {Prerequisites of Isopeptide Bond Formation in Microcystin Biosynthesis}, series = {ChemBioChem : a European journal of chemical biology}, volume = {18}, journal = {ChemBioChem : a European journal of chemical biology}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1439-4227}, doi = {10.1002/cbic.201700389}, pages = {2376 -- 2379}, year = {2017}, abstract = {The biosynthesis of the potent cyanobacterial hepatotoxin microcystin involves isopeptide bond formation through the carboxylic acid side chains of d-glutamate and -methyl d-aspartate. Analysis of the in vitro activation profiles of the two corresponding adenylation domains, McyE-A and McyB-A(2), either in a didomain or a tridomain context with the cognate thiolation domain and the upstream condensation domain revealed that substrate activation of both domains strictly depended on the presence of the condensation domains. We further identified two key amino acids in the binding pockets of both adenylation domains that could serve as a bioinformatic signature of isopeptide bond-forming modules incorporating d-glutamate or d-aspartate. Our findings further contribute to the understanding of the multifaceted role of condensation domains in nonribosomal peptide synthetase assembly lines.}, language = {en} } @article{WeizIshidaQuittereretal.2014, author = {Weiz, Annika R. and Ishida, Keishi and Quitterer, Felix and Meyer, Sabine and Kehr, Jan-Christoph and Mueller, Kristian M. and Groll, Michael and Hertweck, Christian and Dittmann-Th{\"u}nemann, Elke}, title = {Harnessing the evolvability of tricyclic microviridins to dissect protease-inhibitor interactions}, series = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, volume = {53}, journal = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition}, number = {14}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1433-7851}, doi = {10.1002/anie.201309721}, pages = {3735 -- 3738}, year = {2014}, abstract = {Understanding and controlling proteolysis is an important goal in therapeutic chemistry. Among the natural products specifically inhibiting proteases microviridins are particularly noteworthy. Microviridins are ribosomally produced and posttranslationally modified peptides that are processed into a unique, cagelike architecture. Here, we report a combined rational and random mutagenesis approach that provides fundamental insights into selectivity-conferring moieties of microviridins. The potent variant microviridin J was co-crystallized with trypsin, and for the first time the three-dimensional structure of microviridins was determined and the mode of inhibition revealed.}, language = {en} }