TY  - JOUR
A1  - Reyna-González, Emmanuel
A1  - Schmid, Bianca
A1  - Petras, Daniel
A1  - Süssmuth, Roderich D.
A1  - Dittmann, Elke
T1  - Leader Peptide-Free In Vitro Reconstitution of Microviridin Biosynthesis Enables Design of Synthetic Protease-Targeted Libraries
JF  - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition
N2  - 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.
KW  - biosynthesis
KW  - cyanobacteria
KW  - microviridins
KW  - natural products
KW  - peptides
Y1  - 2016
U6  - https://doi.org/10.1002/anie.201604345
SN  - 1433-7851
SN  - 1521-3773
VL  - 55
SP  - 9398
EP  - 9401
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Meyer, Sabine
A1  - Mainz, Andi
A1  - Kehr, Jan-Christoph
A1  - Suessmuth, Roderich
A1  - Dittmann, Elke
T1  - Prerequisites of Isopeptide Bond Formation in Microcystin Biosynthesis
JF  - ChemBioChem : a European journal of chemical biology
N2  - 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.
KW  - amino acids
KW  - biosynthesis
KW  - cyanobacteria
KW  - nonribosomal peptide
KW  - substrate specificity
Y1  - 2017
U6  - https://doi.org/10.1002/cbic.201700389
SN  - 1439-4227
SN  - 1439-7633
VL  - 18
SP  - 2376
EP  - 2379
PB  - Wiley-VCH
CY  - Weinheim
ER  -