Abstract
A number of enzymes employ the unusual amino acid selenocysteine as part of their active site because of its high chemical reactivity. Selenocysteine is incorporated into these proteins co-translationally: biosynthesis occurs on a specific tRNA and insertion into a growing polypeptide is directed by a UGA codon in the mRNA. In E. coli, this requires a specific translation factor. Selenocysteine thus represents a unique expansion of the genetic code.
MeSH terms
-
Animals
-
Base Sequence
-
Codon*
-
Cysteine / analogs & derivatives*
-
Cysteine / biosynthesis
-
Cysteine / genetics
-
Escherichia coli / genetics
-
Genetic Code*
-
Humans
-
Molecular Sequence Data
-
Organoselenium Compounds
-
Protein Biosynthesis*
-
Proteins / genetics
-
RNA, Messenger / genetics
-
RNA, Transfer, Amino Acid-Specific / genetics
-
Selenium / metabolism*
-
Selenocysteine
-
Selenoproteins
Substances
-
Codon
-
Organoselenium Compounds
-
Proteins
-
RNA, Messenger
-
RNA, Transfer, Amino Acid-Specific
-
Selenoproteins
-
Selenocysteine
-
Selenium
-
Cysteine