title: How an obscure archaeal gene inspired the discovery of selenocysteine biosynthesis in humans.
abstract: Selenocysteine (Sec) is the 21st genetically encoded amino acid found in organisms from all three domains of life. Sec biosynthesis is unique in that it always proceeds from an aminoacyl-tRNA precursor. Even though Sec biosynthesis in bacteria was established almost two decades ago, only recently the pathway was elucidated in archaea and eukaryotes. While other aspects of Sec biology have been reviewed previously (Allmang and Krol, Biochimie 2006;88:1561-1571, Hatfield et al., Prog Nucleic Acid Res Mol Biol 2006;81:97-142, Squires and Berry, IUBMB Life 2008;60:232-235), here we review the biochemistry and evolution of Sec biosynthesis and coding and show how the knowledge of an archaeal cysteine biosynthesis pathway helped to uncover the route to Sec formation in archaea and eukaryotes.
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA. d.su@yale.edu
authors.forename: Dan
authors.initials: D
authors.lastname: Su
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Hohn
authors.forename: Sotiria
authors.initials: S
authors.lastname: Palioura
authors.forename: R Lynn
authors.initials: RL
authors.lastname: Sherrer
authors.forename: Jing
authors.initials: J
authors.lastname: Yuan
authors.forename: Dieter
authors.initials: D
authors.lastname: Söll
authors.forename: Patrick
authors.initials: P
authors.lastname: O'Donoghue
mesh_terms: D001105:Archaea / Q000235:genetics* / Q000378:metabolism; D003545:Cysteine / Q000096:biosynthesis*; D019143:Evolution, Molecular; D005815:Genetic Code / Q000235:genetics*; D005823:Genetics / Q000266:history*; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D017279:Selenocysteine / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: D017279:Selenocysteine; D003545:Cysteine