title: Evolution of the genetic code.
abstract: The structure of the genetic code suggests that amino acid biosynthesis and hydrophobicity were important factors in shaping the genetic code, as the primitive code coevolved with new varieties of amino acids generated by the expanding pathways of biosynthesis. The current code is exceptionally stable. Deviant codes nonetheless have been observed in a number of mitochondrial and cellular genomes. Even the membership of encoded amino acids is undergoing expansion to include phosphoserine and selenocysteine. Experimental mutation of the code also has proven feasible, in a replacement of tryptophan by 4-fluorotryptophan as a component constituent of proteins. Such mutations, introducing novel varieties of encoded amino acids, will open up a new dimension in protein engineering and design.
authors.affiliation: Department of Biochemistry, University of Toronto, Canada.
authors.forename: J T
authors.initials: JT
authors.lastname: Wong
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D005075:Biological Evolution; D003062:Codon; D005815:Genetic Code; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009154:Mutation; D000069497:Origin of Life; D015202:Protein Engineering; D012343:RNA, Transfer / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid
chemical_list: D003062:Codon; D012343:RNA, Transfer