DNA is made of four bases – A (adenine), T (thymine), C (cytosine) and G (guanine). Or is it? Researchers at Freie Universität Berlin have created an artificial base and directed the evolution of a bacterium to generate an organism that uses the new base, 5-chlorouracil, instead of thymine. The results were published in Angewandte Chemie – International Edition.
The molecule 5-chlorouracil is normally toxic. The researchers genetically engineered Escherichia coli, making them unable to synthesize thymine, and then cultured them on increasing concentrations of 5-chlorouracil, maintaining selection pressure. After around one thousand generations, the bacteria had randomly mutated and were incorporating around 90% 5-chlorouracil into their DNA.
Following on from the creation of a cell using a synthetic genome, this could make the idea of completely synthetic organosma a step closer. These could be designed to generate high value products such as biofuels, chemicals or pharmaceuticals.
Thanks to Suzanne Elvidge @pharmawrite for this guest blog.