selenocysteine

Term: selenocysteine

Literally meaning: “pertaining to selenium and cysteine”

Origin: Anc Greek

σελήνη/selene(=moon) > selenium (chemical element that was named by  Swedish chemist Jons Jacob Berzelius in 1817 when he noticed that selenium is associated with tellurium(named for the Earth)

+ κύστις /kystis (=sac, or anatomical sac such as bladder)

>κύω/kyo(=carry a baby in a sac)

Coined/History 

 The first article which contains information about selenoprotein was published in 1973 by Thressa Stadtman, who wrote that glycine reductase was a selenoprotein. The first article on “selenocysteine” was published in 1976 and described the chromatographic behaviour of carboxymethylated forms of cysteine and selenocysteine.  

 

 

Definition

Selenocysteine  is an amino acid similar to cysteine but with an atom of selenium taking the place of the usual sulphur. Selenocysteine is encoded by UGA triplet which is normally a stop codon. It is found in many enzymes that called selenoproteins.

 Sources

Pinsent, J. Biochem. J. 1954, 57, 10. Shum, A. C.; Murphy, J. C. J. Bacteriol. 1972, 110, 447.

Bock, A. PNAS 1986, 83, 4650.