Thymine is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine. Thymine (T) almost always pairs with adenine, although thymine dimers also occur due to UV light exposure. This mutation is responsible for melanoma formation. Thymine is also known as 5-methyluracil, a pyrimidine nucleobase. As the name suggests, thymine may be derived by methylation of uracil at the 5th carbon. In RNA,… (More on Thymine)