Encyclopedia > Methionine

  Article Content

Methionine

Methionine (Met, M. C5H11NO2S) is a essential nonpolar amino acid, and a lipotropic[?].

It and cysteine are the only sulfur containing amino acids that are coded for by DNA (Homocysteine is an amino acid and contains sulfur, but is a product of S-adenosylmethionine 1 carbon metabolism and is not coded for by DNA). Methionine is a methyl donor as S-adenosyl methionine[?] (SAM). It is incorporated into the N-terminal position of all proteins (though it may be removed by post-translational modification). It plays a role in cysteine, carnitine[?] and taurine synthesis by the transsulfuration pathway[?], lecithin[?] production, the synthesis of phosphatidylcholine[?] and other phospholipids. Improper conversion of methionine can lead to atherosclerosis. Methionine is a chelating agent.

Most amino acids have a redundant genetic code; several different nucleotide sequences code for the same amino acid, giving a degree of error-correction to the genetic sequence, usually with the third base in the codon being non-specific. Methionine is one of only two amino acids with a single code, AGT. (Tryptophan, coded by AGG, is the other)



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Anna Karenina

... in the periodical Ruskii Vestnik ("Russian Messenger"), but Tolstoy clashed with the editor, Mikhail Katkov, over issues that arose in the final installment. ...

 
 
 
This page was created in 58.1 ms