selenocysteinemedical dictionary

<amino acid>

<biochemistry> An unusual amino acid of proteins, the selenium analogue of cysteine, in which a selenium atom replaces sulphur. Involved in the catalytic mechanism of seleno enzymes such as formate dehydrogenase of E. coli and mammalian glutathione peroxidase. May be co translationally coded by a special opal suppressor tRNAase that recognises certain UGA nonsense codons.

This entry appears with permission from the Dictionary of Cell and Molecular Biology

(11 Mar 2008)