Title: Pyrrolysine
CAS Registry Number: 448235-52-7
CAS Name: N6-[(3R)-1,5-Didehydro-3-methyl-D-prolyl]-L-lysine
Additional Names: L-pyrrolysine
Molecular Formula: C12H21N3O3
Molecular Weight: 255.31
Percent Composition: C 56.45%, H 8.29%, N 16.46%, O 18.80%
Literature References: Naturally occurring, genetically encoded amino acid found in certain methanogenic Archaea; originally described as L-lysine e-amide linked to (4R,5R)-4-substituted-1-pyrroline-5-carboxylate. Identification of pyrrolysine-specific tRNA in Methanosarcina barkeri: G. Srinivasan et al., Science 296, 1459 (2002). Identification as UAG-encoded residue in monomethylamine methyltransferase: B. Hao et al., ibid. 1462. Identification of C4-substituent as a methyl group, synthesis and properties: idem et al., Chem Biol. 11, 1317 (2004). MS analysis: J. A. Soares et al., J. Biol. Chem. 280, 36962 (2005). Reviews: C. Fenske et al., Angew. Chem. Int. Ed. 42, 606-610 (2003); J. A. Krzycki, Curr. Opin. Microbiol. 8, 706-712 (2005).
Derivative Type: Lithium salt
Molecular Formula: C12H20LiN3O3
Molecular Weight: 261.25
Percent Composition: C 55.17%, H 7.72%, Li 2.66%, N 16.08%, O 18.37%
Properties: White solid. [a]D20 -2.1° (c = 0.25 in CH3OH). uv max (methanol): 310 nm (sh) (e 35.4).
Optical Rotation: [a]D20 -2.1° (c = 0.25 in CH3OH)
Absorption maximum: uv max (methanol): 310 nm (sh) (e 35.4)
Pyruvate Decarboxylase Pyruvic Acid Pyrvinium Pamoate Q-Enzyme Quantum Dye

CAS number 448235-52-7 N
PubChem 5460671
ChemSpider 4574156 YesY
KEGG C16138 YesY
ChEBI CHEBI:58499 YesY
Jmol-3D images Image 1
Molecular formula C12H21N3O3
Molar mass 255.31 g mol−1
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Pyrrolysine (abbreviated as Pyl or O) is a naturally occurring, genetically coded amino acid used by some methanogenic archaea and one known bacterium in enzymes that are part of their methane-producing metabolism. It is similar to lysine, but with an added pyrroline ring linked to the end of the lysine side chain. It forms part of an unusual genetic code in these organisms, and is considered the 22nd proteinogenic amino acid.

The joint nomenclature committee of the IUPAC/IUBMB has officially recommended the three-letter symbol Pyl and the one-letter symbol O for pyrrolysine.[1]