Table 1.

Rate constants for hydrolysis and aminolysis derived from nucleophile partitioning experiments

	Kobs-HA (s−1)	Fold increase (HA)	Kobs-water (s−1)	Fold increase (water)	Fold RF defect
Solution	5.3×10−3 ± 0.7×10−3	19	2.3×10−5	2
Ribosome	2.9×10−4 ± 0.2×10−4		1.2×10−5 ± 0.4×10−5
tRNA	1.3×10−3 ± 0.3×10−3	5	5.9×10−4 ± 2.3×10−4	50
RF1	cnd		0.65 ± 0.06	53000
Ribosome Mutants
A2602C	1.8×10−4 ± 0.4×10−4	1	1.0×10−3 ± 0.3×10−3	85	620
U2585C	5.6×10−4 ± 0.3×10−4	2	8.2×10−3 ± 0.9×10−3	670	79
RF1 Mutants
G233A	3.6×10−4 ± 2.4×10−4	1	1.2×10−3 ± 0.6×10−3	97	540
G234A	2.9×10−4 ± 0.6×10−4	1	8.4×10−5 ± 2.6×10−5	7	7700
Q235W	cnd		0.086 ± 0.003	7000	7
Q235K	cnd		0.17 ± 0.04	14000	4
Q235E	cnd		0.27 ± 0.05	22000	2
Q235N	2.1×10−5 ± 0.3×10−5	−14	8.5×10−5 ± 2.0×10−5	7	7600
Q235D	1.1×10−5 ± 0.1×10−5	−26	6.8×10−5 ± 0.4×10−5	6	9500
Q235L	cnd		0.0086 ± 0.0026	700	75
Q235T	cnd		0.016 ± 0.004	1300	41
Q235S	4.4×10−3 ± 0.6×10−3	15	0.068 ± 0.009	5500	10
Q235A	3.3×10−2 ± 0.5×10−2	113	0.18 ± 0.02	14000	4
Q235G	4.7×10−2 ± 0.8×10−2	165	0.021 ± 0.009	1700	30

cnd = could not determine