Abstract

AgBiotech - Tools for Plant Genome Engineering and Genome Reprogramming

Jens Boch, Scientist, Martin-Luther-University Halle-Wittenberg

Natural TALEs from plant-pathogenic Xanthomonas bacteria function as plant transcription factors and are today the most potent designer gene inducers in plants. TALE proteins bind to DNA using a central repeat domain with each repeat recognizing one base in the target DNA sequence via one amino acid. This simple and modular repeat architecture allows rearrangement of TALE repeats to generate artificial TALE proteins with virtually any tailored DNA-binding specificity. Highly specific TALE nucleases (TALENs) can be engineered to modify genomic sequences in a variety of eukaryotic organisms. Modular cloning allows assembly of TALE-derivatives in a matter of days. Careful design enabled us to build TALENs with an unparalleled target specificity. The TALENs differentiate between sequences that only differ in one base pair allowing for allele-specific modifications. In contrast, the use of repeat variants added a designer flexibility to TALEs to simultaneously target highly variable allelic sites. This flexibility can also be exploited to create a cascade of TALE master regulators for synthetic circuits. In summary, the TALE DNA-binding domain is exceptionally versatile to build designer tools for genome engineering.