. Author manuscript; available in PMC: 2020 Jun 21.

Published in final edited form as: ACS Chem Biol. 2019 Jun 7;14(6):1068–1076. doi: 10.1021/acschembio.9b00202

Table 2.

Observed and relative rates for G33I mutation and substrate thio substitutions, S(R_P/S_P), in twister ribozyme compared to wild type (WT).

Sys^a	Variant^b	Ions^c	k_obs (min⁻¹)^d	k/k′^e	k_o/k_s^f	Rescue^g
Twr	WT		2.45 ± 0.04
	S(R_P)	Mg²⁺	0.026 ± 0.002	94	94
	S(S_P)		3.3 ± 0.2	0.7	0.7
	WT	Mg²⁺	0.8 ± 0.1	3.1		(metal)
	S(R_P)	+	0.007 ± 0.002	350	114	0.8
	S(S_P)	Mn²⁺	3.7 ± 0.4	0.7	0.2	3.2
	G33I		0.0057 ± 0.0005	430		(mutational)
	G33I/S(R_P)	Mg²⁺	0.0060 ± 0.0003	410	0.95	99
	G33I/S(S_P)		0.004 ± 0.001	610	1.4	0.5

Ribozyme system, Twr: twister ribozyme.

Identity of the all chemical modifications to the wild type (WT) ribozyme/substrate.

Molarity of each indicated divalent ion present is 10mM.

All experimental values from reference³⁸.

k/k′ values are obtained using the WT in 10 mM Mg²⁺ conditions (first row).

k_O/k_S values are for oxo and thio substituted substrates for a given variant under a single set of ionic conditions.

Rescue effects are shown for metal ion rescue, (k_O/k_S)^Mg2+/(k_O/k_S)^Mn2+, and mutational rescue, ((k_O/k_S)^WT/(k_O/k_S)^Mut).