We now know that KRAS is a plasma membrane–bound protein 21 and a member of a large family of hundreds of different proteins known as GTPases, enzymes that bind to the nucleotide guanosine ...

It pairs with cytosine (C) through three hydrogen bonds, providing stability to the DNA double helix. Guanine is also a component of important biomolecules such as GTP (guanosine triphosphate), which ...