Adenine

=Adenine=

**Adenine **  (often abbreviated to **A ** , chemical formula C5H5N5) is a nitrogenous nucleobase, one of the four commonly found in DNA . When forming part of a deoxynucleotide, the compound is called **deoxyadenosine monophosphate **  (dAMP), and it is attached to a growing DNA chain by addition of a **deoxyadenosine triphosphate ** (dATP) precursor. It may also be found in RNA  where its monomeric constituent is called simply <span style="font-family: Arial,Helvetica,sans-serif;">**<span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">adenosine monophosphate ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">(AMP) from a <span style="font-family: Arial,Helvetica,sans-serif;">**<span style="font-family: Arial,Helvetica,sans-serif; font-size: 90%;">adenosine triphosphate ** <span style="font-family: Arial,Helvetica,sans-serif; font-size: 11.34px;"> (ATP) precursor.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 11.34px;"> Adenine is a purine derivative, and it base-pairs with thymine in DNA or uracil in RNA, in both cases using two hydrogen bonds. It may sometimes be found <span style="font-family: Arial,Helvetica,sans-serif; font-size: 11.34px;">methylated <span style="font-family: Arial,Helvetica,sans-serif; font-size: 11.34px;"> in eukaryotic genomes, where the sixth nitrogen on the purine ring has a methyl group attached to form N6-methyladenine.