This domain is found in 3-methyl-D-ornithine--L-lysine ligase from Methanosarcina barkeri (PylC) and similar sequences from prokaryotes. PylC is required for the biosynthesis of pyrrolysine. This ATP-grasp enzyme is composed of three domains. This entry represents the N-terminal domain, which is composed of a central four-stranded beta-sheet that is faced on both sides by two helices. It shows an adenine binding pocket that has not been observed in any homologous structure determined before [1].

1: Biosynthesis of the 22nd genetically encoded amino acid pyrrolysine: structure and reaction mechanism of PylC at 1.5A resolution. Quitterer F, List A, Beck P, Bacher A, Groll M; J Mol Biol. 2012;424:270-282. PMID:22985965