TY  - JOUR
A1  - Gatte-Picchi, Douglas
A1  - Weiz, Annika
A1  - Ishida, Keishi
A1  - Hertweck, Christian
A1  - Dittmann-Thünemann, Elke
T1  - Functional analysis of environmental DNA-derived microviridins provides new insights into the diversity of the tricyclic peptide family
JF  - Applied and environmental microbiology
N2  - Microviridins represent a unique family of ribosomally synthesized cage-like depsipeptides from cyanobacteria with potent protease-inhibitory activities. The natural diversity of these peptides is largely unexplored. Here, we describe two methodologies that were developed to functionally characterize cryptic microviridin gene clusters from metagenomic DNA. Environmental samples were collected and enriched from cyanobacterial freshwater blooms of different geographical origins containing predominantly Microcystis sp. Microviridins were produced either directly from fosmid clones or after insertion of environmental DNA-derived gene cassettes into a minimal expression platform in Escherichia coli. Three novel microviridin variants were isolated and tested against different serine-type proteases. The comparison of the bioactivity profiles of the new congeners allows deduction of further structure-function relationships for microviridins. Moreover, this study provides new insights into microviridin processing and gene cluster organization.
Y1  - 2014
U6  - https://doi.org/10.1128/AEM.03502-13
SN  - 0099-2240
SN  - 1098-5336
VL  - 80
IS  - 4
SP  - 1380
EP  - 1387
PB  - American Society for Microbiology
CY  - Washington
ER  - 
TY  - JOUR
A1  - Weiz, Annika R.
A1  - Ishida, Keishi
A1  - Quitterer, Felix
A1  - Meyer, Sabine
A1  - Kehr, Jan-Christoph
A1  - Mueller, Kristian M.
A1  - Groll, Michael
A1  - Hertweck, Christian
A1  - Dittmann-Thünemann, Elke
T1  - Harnessing the evolvability of tricyclic microviridins to dissect protease-inhibitor interactions
JF  - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition
N2  - 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.
KW  - cyanobacteria
KW  - peptide engineering
KW  - protease inhibitors
KW  - RiPPs
KW  - structure elucidation
Y1  - 2014
U6  - https://doi.org/10.1002/anie.201309721
SN  - 1433-7851
SN  - 1521-3773
VL  - 53
IS  - 14
SP  - 3735
EP  - 3738
PB  - Wiley-VCH
CY  - Weinheim
ER  -