title: Generation of a bacterium with a 21 amino acid genetic code.
abstract: We have generated a completely autonomous bacterium with a 21 amino acid genetic code. This bacterium can biosynthesize a nonstandard amino acid from basic carbon sources and incorporate this amino acid into proteins in response to the amber nonsense codon. The biosynthetic pathway for the amino acid p-aminophenylalanine (pAF) as well as a unique pAF synthetase and cognate tRNA were added to Escherichia coli. Denaturing gel electrophoresis and mass spectrometric analysis show that pAF is incorporated into myoglobin with fidelity and efficiency rivaling those of the common 20 amino acids. This and other such organisms may provide an opportunity to examine the evolutionary consequences of adding new amino acids to the genetic repertoire, as well as generate proteins with new or enhanced biological functions.
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Mehl
authors.forename: J Christopher
authors.initials: JC
authors.lastname: Anderson
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Santoro
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Martin
authors.forename: David S
authors.initials: DS
authors.lastname: King
authors.forename: David M
authors.initials: DM
authors.lastname: Horn
authors.forename: Peter G
authors.initials: PG
authors.lastname: Schultz
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005818:Genetic Engineering / Q000379:methods; D016680:Genome, Bacterial; D017017:Methanococcus / Q000201:enzymology / Q000235:genetics; D009211:Myoglobin / Q000096:biosynthesis / Q000235:genetics; D010649:Phenylalanine / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000235:genetics*; D012345:RNA, Transfer, Amino Acid-Specific / Q000096:biosynthesis / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D009211:Myoglobin; D012345:RNA, Transfer, Amino Acid-Specific; C009722:4-aminophenylalanine; D010649:Phenylalanine; D000604:Amino Acyl-tRNA Synthetases