. Author manuscript; available in PMC: 2011 Feb 12.

Published in final edited form as: J Mol Biol. 2009 Nov 28;396(1):195–208. doi: 10.1016/j.jmb.2009.11.039

Table 2.

Affinities of B. subtilis RNase P reconstituted with wild type and mutant P proteins for A(−4) and G(−4) pre-tRNA^Asp.

Protein	K_{D, obs} (nM) 3.5 mM [Ca²⁺]_f^a

	G(−4)	A(−4)	G(−4) / A(−4)
Wild Type	11 ± 3	5 ± 1	2.2
F16A	380 ± 70	260 ± 90	1.5
F16C	285 ± 63	112 ± 54	2.5
F20A	39 ± 11	38 ± 13	1.0
S25A	43 ± 16	14 ± 5	3.1
Y34A	32 ± 11	57 ± 33	0.6
R60A	44 ± 13	68 ± 19	0.6
N61A	51 ± 21	35 ± 17	1.5
K64A	60 ± 21	33 ± 12	1.8
R65A	155 ± 40	73 ± 22	2.1

Conditions: 50 mM MES, 50 mM Tris, pH 6.0, 37°C, 3.5 [Ca²⁺]_f. 400 mM [KCl] was used to maintain ionic strength as described in Materials and Methods.