Reactivity and chemical synthesis of L-pyrrolysine- the 22(nd) genetically encoded amino acid

Chem Biol. 2004 Sep;11(9):1317-24. doi: 10.1016/j.chembiol.2004.07.011.


L-pyrrolysine, the 22(nd) genetically encoded amino acid, was previously deduced to be (4R, 5R)-4-substituted-pyrroline-5-carboxylate attached to the epsilon-nitrogen of lysine based on the crystal structure of the M. barkeri monomethylamine methyltransferase (MtmB). To confirm L-pyrrolysine's identity, structures of MtmB have been determined following treatment with hydroxylamine, N-methylhydroxylamine, or dithionite. Analysis of these structures has provided additional support for the presence of the pyrroline ring and, together with previous mass spectroscopy data, has led us to assign the C(4)-substituent to a methyl group. Based on this assignment, synthetic L-pyrrolysine was prepared by chemical methods. Detailed study of this chemically synthesized L-pyrrolysine has allowed us to characterize its physical properties, to study its chemical stability, and to elucidate the role of its C(4) substituent. Future applications of this synthetic L-pyrrolysine include its in vivo incorporation into recombinant proteins.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Archaeal Proteins
  • Crystallography, X-Ray
  • Dithionite / chemistry
  • Hydroxylamine / chemistry
  • Hydroxylamines / chemistry
  • Lysine / analogs & derivatives*
  • Lysine / chemical synthesis
  • Lysine / chemistry*
  • Methanosarcina barkeri / enzymology*
  • Methyltransferases / chemistry*
  • Models, Molecular
  • Molecular Sequence Data
  • Molecular Structure


  • Archaeal Proteins
  • Hydroxylamines
  • Dithionite
  • Hydroxylamine
  • Methyltransferases
  • monomethylamine methyltransferase
  • pyrrolysine
  • Lysine
  • N-methylhydroxylamine

Associated data

  • PDB/1TV2
  • PDB/1TV3
  • PDB/1TV4