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Revision as of 19:42, 26 October 2012 by Davsie (Talk | contribs)




TALE technology currently revolutionizes synthetic biology, not only because of higher sequence fidelity or less cytotoxicity compared to other DNA binding proteins (e.g. zinc fingers). The main advantage is that they can be produced rationally to bind a DNA sequence of choice, whereas zinc fingers with the desired binding properties need to be selected from a library of fingers. That is why this technology is generally much less costly, time consuming and does guarantee binding sites for every predefined sequence than the zinc finger technology, although open source platforms have also been published for the latter1.

Consequently, deciphering the TAL code also resulted in an enormous step towards democratizing targeted DNA manipulation2. Moreover, multiple protocols and open source kits have been published by the most influential labs in the field over the past year, which further popularized TALEs3,4,5. However, we believe that the last step of democratizing precise gene targeting has not been made yet – this hypothesis is corroborated by the fact that the biotech companies Cellectis bioresearch and Invitrogen have launched quite expensive new TAL effector product lines during the last few months. In order to bring TAL technology within reach for everyone, in particular for future iGEM students, we identified the two main bottlenecks of conventional TALE assembly, namely that it is very time consuming and requires substantial training in molecular biology. In the next steps, we invented a method, that we refer to as Golden Gate cloning- based, automatable TAL Effector (GATE) assembly, and built the genetic parts (the GATE assembly toolkit) to actually assemble custom TALEs at record speed. Furthermore, we quantified the efficiency of our GATE assembly and tested our constructs in a Human Embryonic Kidney (HEK) cell line. We are proud to say that with our GATE assembly kit, future iGEM students will be able to easily assemble custom 12.5 repeat TALEs faster than anyone else in the world. While working on the GATE assembly kit, we learned a lot about Golden Gate cloning and came up with a strategy to introduce this powerful cloning technology to the iGEM registry as the Golden Gate standard without compromising existing standards. Our major goal was to empower future iGEM students to use and further develop TALE technology. That is why we dedicated a whole subsection of our project description to a step-by-step GATE assembly protocol. We believe that by enabling virtually anyone to specifically manipulate any locus even in the context of a whole genome, we have done the last step towards democratizing gene targeting. Although to date, the GATE assembly kit is complete for only a few weeks, we regularly receive requests from research groups all over Europe, asking for copies of the kit. Moreover, we got approached by the open source plasmid repository Addgene that wants to distribute our toolkit. We are currently preparing to send our kit to them so the GATE kit will be available to everyone soon! That way, have a significant impact also on the research world around iGEM.




Golden Gate Standard


The TAL Vector


GATE Assembly Kit


Using the Toolkit


The Future of TAL


Experiments and Results




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