Since the structure of DNA was discovered more than 60 years ago, it’s been known that there are four DNA bases: G, C, A and T (Guanine, Cytosine, Adenine and Thymine). The way these bases are ordered determines the makeup of the genome.
The new study has found that this rare ‘extra’ base, known as 5-formylcytosine (5fC) is stable in living mouse tissues. While its exact function is yet to be determined, 5fC’s physical position in the genome makes it likely that it plays a key role in gene activity and regulation.
The researchers believe that 5fC might alter the way DNA is recognised by proteins. ‘Unmodified DNA interacts with a specific set of proteins, and the presence of 5fC could change these interactions either directly or indirectly by changing the shape of the DNA duplex.