Post on 19-Dec-2015
Editing Domain (“2nd Sieve”)
Catalytic Domain (“1st Sieve”)
Anticodon Binding Domain
C-Terminal Coiled-Coil Domain
862 amino acids 25 α-helices 30 β-strands
Overall Structure
Function
• Aminoacyl tRNA synthetases are enzymes that catalyze the esterification of a specific amino acid to a compatible cognate tRNA to form an aminoacyl-tRNA
• Class I vs. Class II:– 2’-OH, then 3’-OH– Directly to 3’-OH
Kinetics for C-term. Domaino phosphates on A20 & A21 interact through salt bridges with Arg818 and Arg843
o G19 & C56 crucial of correct positioning of 3’ CCA end of tRNA into aminoacylation catalytic site
References1. Fukai, S.; Nureki, O.; Sekine, S.; Shimada, A.; Tao, J.; Vassylyev, D.G.; Yokoyama, S.
Structural Basis for Double-Sieve Discrimination of L-Valine from L-Isoleucine and L-Threonine by the Complex of tRNAVal and Valyl-tRNA Synthetase. Cell 2000, 103, 793-803.
2. Fukai, S.; Nureki, O.; Sekine, S.; Shimada, A.; Vassylyev, D.G.; Yogoyama, S. Mechanism of molecular interactions for tRNAVal recognition by valyl-tRNA synthetase. RNA 2003, 9, 100-111.
3. Fukunaga, R.; Yokoyama, S. Structural Basis for Non-cognate Amino Acid Discrimination by the Valyl-tRNA Synthetase Editing Domain. J. Bio. Chem. 2005, 280 (33), 29937-29945.
4. Liu, M.; Chu, W.; Liu, J.C.H.; Horowitz, J. Role of acceptor stem conformation in tRNAVal
recognition by its cognate synthetase. Nucleic Acids Res. 1997, 25, 4883-4890.