2AG6

Crystal structure of p-bromo-l-phenylalanine-tRNA sythetase in complex with p-bromo-l-phenylalanine

Summary for 2AG6

• Entry DOI: 10.2210/pdb2ag6/pdb
• Related: 1J1U 1ZH0 1ZH6
• Descriptor: Tyrosyl-tRNA synthetase, 4-BROMO-L-PHENYLALANINE (3 entities in total)
• Functional Keywords: structural plasticity, unnatural amino acid, trna synthetase, bromo-phenylalanine, ligase
• Biological source: Methanocaldococcus jannaschii
• Cellular location: Cytoplasm: Q57834
• Total number of polymer chains: 1
• Total formula weight: 36323.97

Authors

Turner, J.M.,Graziano, J.,Spraggon, G.,Schultz, P.G. (deposition date: 2005-07-26, release date: 2006-04-04, Last modification date: 2023-11-15)

Primary citation

Turner, J.M.,Graziano, J.,Spraggon, G.,Schultz, P.G.
Structural plasticity of an aminoacyl-tRNA synthetase active site
Proc.Natl.Acad.Sci.Usa, 103:6483-6488, 2006

PubMed Abstract: Recently, tRNA aminoacyl-tRNA synthetase pairs have been evolved that allow one to genetically encode a large array of unnatural amino acids in both prokaryotic and eukaryotic organisms. We have determined the crystal structures of two substrate-bound Methanococcus jannaschii tyrosyl aminoacyl-tRNA synthetases that charge the unnatural amino acids p-bromophenylalanine and 3-(2-naphthyl)alanine (NpAla). A comparison of these structures with the substrate-bound WT synthetase, as well as a mutant synthetase that charges p-acetylphenylalanine, shows that altered specificity is due to both side-chain and backbone rearrangements within the active site that modify hydrogen bonds and packing interactions with substrate, as well as disrupt the alpha8-helix, which spans the WT active site. The high degree of structural plasticity that is observed in these aminoacyl-tRNA synthetases is rarely found in other mutant enzymes with altered specificities and provides an explanation for the surprising adaptability of the genetic code to novel amino acids.

PubMed: 16618920
DOI: 10.1073/pnas.0601756103

Experimental method

X-RAY DIFFRACTION (1.9 Å)