Natalie Krahn

Selenocysteine, the 21st amino acid, is found in all three domains of life and is inserted at UGA codons. Nature has sophisticated mechanisms to distinguish canonical UGA stop codons from UGA codons designated for Selenocysteine (Sec) insertion. We are interested in studying the role of this amino acid in natural proteins and also harnessing its enhanced chemical properties to build novel proteins with Sec (selenoproteins).

In order to accomplish this, we need a way to recombinantly express selenoproteins. However, due to its naturally complex biosynthesis machinery this is not straightforward. Using synthetic biology, our lab focuses on building efficient translation machinery to insert Sec. We have started with a bacterial and yeast system but are expanding to mammalian systems and potentially even archaea. Our patented technology paves the way to study the role of Sec in proteins.

Humans have 25 selenoproteins that are essential for our function, therefore there is no surprise they are connected to a plethora of diseases. The ability to express these selenoproteins and to control their post-translational modifications, we can begin to unravel these connections, with the over-arching idea of using selenium supplementation for treatment. The other application of this technology is to build novel selenoproteins that can be used in industry, or as tools in basic research. For example, one of our collaborations is involved in building hydrogenases with Sec that are can be used to generate clean energy.