. 2016 Nov 11;113(48):13744–13749. doi: 10.1073/pnas.1610917113

Table S3.

Kinetic parameters for GTP hydrolysis and peptidyl transfer from ternary complex with T-stem mutated tRNA^Phe

	UUC (Cognate)	CUC				UCC				UUA
Mutants	(k_cat/K_m)_GTP	(k_cat/K_m)_GTP	(k_cat/K_m)_dip	I x (10³)	F	(k_cat/K_m)_GTP	(k_cat/K_m)_dip	I x (10³)	F	(k_cat/K_m)_GTP	(k_cat/K_m)_dip	I x (10³)	F
	(µM^-1s^-1)	(mM^-1s^-1)				(mM^-1s^-1)				(mM^-1s^-1)
WT	47 ± 11	65 ± 3	1.09 ± 0.18	0.72 ± 0.17	59 ± 10	2.5 ± 0.2	0.15 ± 0.03	19 ± 5	17 ± 4	25 ± 2	0.54 ± 0.06	1.8 ± 0.5	47 ± 7
T1	44 ± 8	90 ± 4	0.38 ± 0.02	0.48 ± 0.09	239 ± 15	2.0 ± 0.1	0.080 ± 0.016	22 ± 4	25 ± 5	23 ± 2	0.18 ± 0.02	1.9 ± 0.4	127 ± 16
T2	46 ± 11	94 ± 7	0.79 ± 0.11	0.49 ± 0.12	118 ± 18	2.1 ± 0.2	0.091 ± 0.010	22 ± 6	23 ± 3	18 ± 1	0.23 ± 0.01	2.6 ± 0.6	78 ± 7
W1	41 ± 11	67 ± 5	1.70 ± 0.09	0.61 ± 0.17	39 ± 3	2.6 ± 0.4	0.18 ± 0.01	16 ± 5	14 ± 2	26 ± 4	0.94 ± 0.15	1.6 ± 0.5	28 ± 6

Kinetic efficiency for cognate and near-cognate GTP hydrolysis, (k_cat/K_m)_GTP, were estimated from experiments with ribosomes at 1 and 2 µM, which are always in excess over ternary complex. The rate of GTP hydrolysis at 2 µM was always twice that at 1 µM with virtually identical k_cat/K_m estimates. Kinetic efficiencies for near-cognate dipeptide formation, (k_cat/K_m)_dip, were derived from titrations of ternary complex in excess over ribosomes. Initial selection (I) was calculated from the ratio of cognate to near-cognate (k_cat/K_m)_GTP parameters. Proofreading factor (F) was calculated from the ratio between near-cognate k_cat/K_m-values for GTP hydrolysis and dipeptide formation (see SI Materials and Methods). Data represent weighted averages from at least two independent experiments ± propagated SD.