title: β-Lysine discrimination by lysyl-tRNA synthetase.
abstract: Elongation factor P is modified with (R)-β-lysine by the lysyl-tRNA synthetase (LysRS) paralog PoxA. PoxA specificity is orthogonal to LysRS, despite their high similarity. To investigate α- and β-lysine recognition by LysRS and PoxA, amino acid replacements were made in the LysRS active site guided by the PoxA structure. A233S LysRS behaved as wild type with α-lysine, while the G469A and A233S/G469A variants decreased stable α-lysyl-adenylate formation. A233S LysRS recognized β-lysine better than wildtype, suggesting a role for this residue in discriminating α- and β-amino acids. Both enantiomers of β-lysine were substrates for tRNA aminoacylation by LysRS, which, together with the relaxed specificity of the A233S variant, suggest a possible means to develop systems for in vivo co-translational insertion of β-amino acids.
authors.affiliation: Ohio State Biochemistry Program, Center for RNA Biology, Ohio State University, Columbus, OH 43210, USA.
authors.forename: Marla S
authors.initials: MS
authors.lastname: Gilreath
authors.forename: Hervé
authors.initials: H
authors.lastname: Roy
authors.forename: Tammy J
authors.initials: TJ
authors.lastname: Bullwinkle
authors.forename: Assaf
authors.initials: A
authors.lastname: Katz
authors.forename: William W
authors.initials: WW
authors.lastname: Navarre
authors.forename: Michael
authors.initials: M
authors.lastname: Ibba
mesh_terms: D019943:Amino Acid Substitution; D001409:Bacillus cereus / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D008239:Lysine / Q000737:chemistry* / Q000235:genetics; D008250:Lysine-tRNA Ligase / Q000737:chemistry* / Q000235:genetics; D020125:Mutation, Missense; D010445:Peptide Elongation Factors / Q000737:chemistry* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D010445:Peptide Elongation Factors; C020746:factor EF-P; D008250:Lysine-tRNA Ligase; D008239:Lysine