Table 1.

Data collection statistics for native and derivative crystals

Crystal	Soaking conditions	Maximum resolution, Å	No. of reflections		Completeness, %	Rmerge, %	Rderi, %	Rano, %	No. of sites	Phasing power
			Total	Unique						Isomorphous	Anomalous
TRI-1
Native		2.4	65,888	19,708	94.8	4.34
EMTS	1 mM, 3 hr	2.4	58,320	18,603	92.4	5.97	5.9	2.4	3	2.57	2.58
TR-II
Native		2.0	103,356	14,339	81.8	8.74
KAu(CN)2	1 mM, 6 days	2.6	46,382	8,069	94.8	8.61	4.4	2.5	2	1.58	1.35
HgCl2	0.1 mM, 8 hr	2.6	52,405	8,374	97.7	6.08	3.3	1.3*	2	1.48	1.19*

R_merge = ∑_h∑_i|I_h,i − 〈I_h〉|/∑_h∑_iI_h,i, where I_h,i is the intensity of reflection h in data set i and 〈I_h〉 is the mean intensity of reflection h in the replicated data. R_deri = ∑∥F_PH| − |F_P∥/∑(|F_PH| + |F_P|), where |F_PH| and |F_P|, respectively, are the structure factor amplitude of the derivative and native crystals. R_ano = ∑∥F_PH(+)| − |F_PH(−)∥/∑(|F_PH(+)| + |F_PH(−)|), where |F_PH(+)| and |F_PH(−)| are the structure factor amplitude of a Friedel pair. Phasing power = (∑|F_H|²/∑(|F_PHobs| − |F_PHcalc|)²]^1/2, where |F_H| is the calculated structure factor amplitude of the heavy atom structure and |F_PHobs| and |F_PHcalc|, respectively, are the observed and calculated structure factor amplitudes of the derivative crystals. 

^*Anomalous difference phase calculation of the HgCl₂ derivative was done by using reflection data to 3.0-Å resolution.