TABLE 1.

Data collection and phasing statistics

Statistic	Valuea
	Mg2+ complex	3′dGTP complex
Wavelength (Å)	1.0	1.0
Cell parameters (Å) for space group C2221
a	160.15	163.71
b	180.47	180.91
c	57.98	58.04
Resolution range (Å)	48-1.85	48-2.6
No. of observed reflections	355,151	131,992
No. of unique reflectionsa	72,065 (8,212)	26,929 (3,067)
Completeness (%)	99.9 (100)	99.6 (100)
Multiplicity	4.9 (4.9)	4.9 (4.9)
Rmergeb	0.09 (0.540)	0.10 (0.627)
I/σ (I)	14.62 (2.98)	13.98 (2.54)
Solvent content (%)	58.9	59.9

^aThe numbers in parentheses refer to the last (highest) resolution shell.

^bR_merge = Σ_hΣ_i|I_hi − <I_h>|/Σ_h,iI_hi, where I_hi is the ith observation of the reflection h, while <I_h> is its mean intensity.