Editing Thymine (section)

==Derivation==
As its alternate name (5-methyluracil) suggests, thymine may be derived by [[methylation]] of uracil at the 5th carbon. In [[RNA]], thymine is replaced with [[uracil]] in most cases.  In DNA, thymine (T) binds to [[adenine]] (A) via two hydrogen bonds, thereby stabilizing the nucleic acid structures.

Thymine combined with [[deoxyribose]] creates the [[nucleoside]] [[deoxythymidine]], which is synonymous with the term [[thymidine]]. Thymidine can be phosphorylated with up to three phosphoric acid groups, producing [[dTMP]] ('''d'''eoxy'''t'''hymidine '''m'''ono'''p'''hosphate), [[dTDP]], or [[dTTP]] (for the '''d'''i- and '''t'''ri- phosphates, respectively).

One of the common mutations of DNA involves two adjacent thymines or cytosine, which, in presence of [[Ultraviolet|ultraviolet light]], may form [[thymine dimers]], causing "kinks" in the DNA molecule that inhibit normal function.

Thymine could also be a target for actions of 5-[[fluorouracil]] (5-FU) in [[cancer]] treatment. 5-FU can be a metabolic analog of thymine (in DNA synthesis) or uracil (in RNA synthesis).  Substitution of this analog inhibits [[DNA replication|DNA synthesis]] in actively dividing cells.

Thymine bases are frequently oxidized to [[hydantoin]]s over time after the death of an organism.<ref>{{cite journal
| last1      = Hofreiter
| first1     = Michael
| last2      = Serre
| first2     = David
| last3      = Poinar
| first3     = Henrik N.
|authorlink3 = Hendrik Poinar
| last4      = Kuch
| first4     = Melanie
| last5      = Pääbo
| first5     = Svante
|authorlink5 = Svante Pääbo
| date       = 2001-05-01
| title      = Ancient DNA
| url        = 
| journal    = [[Nature Reviews Genetics]]
| volume     = 2
| issue      = 5
| pages      = 353–359
| doi        = 10.1038/35072071
| pmid = 11331901
| s2cid = 205016024
| access-date = 
}}
</ref>