PT  - JOURNAL ARTICLE
AU  - Jan Mathony
AU  - Zander Harteveld
AU  - Carolin Schmelas
AU  - Julius Upmeier zu Belzen
AU  - Sabine Aschenbrenner
AU  - Mareike D. Hoffmann
AU  - Christina Stengl
AU  - Andreas Scheck
AU  - Stéphane Rosset
AU  - Dirk Grimm
AU  - Roland Eils
AU  - Bruno E. Correia
AU  - Dominik Niopek
TI  - Computational design of anti-CRISPR proteins with improved inhibition potency and expanded specificity
AID  - 10.1101/685032
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 685032
4099  - http://biorxiv.org/content/early/2019/06/27/685032.short
4100  - http://biorxiv.org/content/early/2019/06/27/685032.full
AB  - Anti-CRISPR (Acr) proteins are bacteriophage-derived antagonists of CRISPR-Cas systems. To date, Acrs were obtained either by mining sequence databanks or experimentally screening phage collections, both of which yield a limited repertoire of naturally occurring variants. Here, we applied structure-based engineering on AcrIIC1, a broad-spectrum inhibitor of type II-C CRISPR systems, to improve its efficacy and expand its specificity. We first show that fusing exogenous protein domains into AcrIIC1 dramatically enhances inhibition of the natural Neisseria meningitidis Cas9 target. Then, using structure-guided design, we converted AcrIIC1 into AcrX, a potent inhibitor of the type II-A CRISPR-Cas9 from Staphylococcus aureus widely applied for in vivo genome editing. Our work introduces designer Acrs as important biotechnological tools and provides an innovative strategy to safeguard the CRISPR technology.