6.1.1.2	ATP + L-tryptophan + tRNATrp = AMP + diphosphate + L-tryptophyl-tRNATrp	-	-	
6.1.1.2	ATP + L-tryptophan + tRNATrp = AMP + diphosphate + L-tryptophyl-tRNATrp	2-step reaction, tRNATrp substrate recognition, mechanism and modeling	649736	
6.1.1.2	ATP + L-tryptophan + tRNATrp = AMP + diphosphate + L-tryptophyl-tRNATrp	a nested, nonlinear model for the sum of metal-free and metal-catalyzed activities and its use in determining metal-free enzyme activity jointly with transition-state metal binding affinity is described, by fitting observed values obtained from Mg2+-depleted assays with increasing EDTA concentrations at known Mg2+ concentrations. Trp activation by TrpRS falls asymptotically to a plateau value 5 orders of magnitude below that observed for the Mg2+-supplemented enzyme at EDTA concentrations that reduce the free metal concentration to below 1 pmolar. The fitted regression model parameters yield a relative rate acceleration of 93000 attributable to the catalytic effect of Mg2+ and an enhanced transition state binding of Mg2+. Factorial analysis indicates that 80% of the reduction in free energy of activation effected by TrpRS arises from protein-ligand interactions	692756	
6.1.1.2	ATP + L-tryptophan + tRNATrp = AMP + diphosphate + L-tryptophyl-tRNATrp	active site, 2 critical positions for amino acid discrimination	653590	
6.1.1.2	ATP + L-tryptophan + tRNATrp = AMP + diphosphate + L-tryptophyl-tRNATrp	random, bi-bi kinetic scheme mechanism, KMSKS motif loop is involved in the catalytic mechanism	652900	
6.1.1.2	ATP + L-tryptophan + tRNATrp = AMP + diphosphate + L-tryptophyl-tRNATrp	recognition of Trp is by an induced-fit mechanism involving conformational change of the AIDQ motif that creates a perfect pocket for the binding and activation of Trp and causes coupled movements of the N-terminal and C-terminal domains. The KMSAS loop has an inherent flexibility and binding of ATP stabilizes it in a closed conformation that secures the position of ATP for catalysis. Structural data indicate that the catalytic mechanism of the Trp activation reaction by hTrpRS involves more moderate conformational changes of the structural elements at the active site compared to bacterial TrpRS	694430	
6.1.1.2	ATP + L-tryptophan + tRNATrp = AMP + diphosphate + L-tryptophyl-tRNATrp	wide opening active site that adopts a compact conformation, modeling of substrate recognition and binding	652565