Table 1. X-ray diffraction data and refinement statistics.

Values in parentheses are for the highest resolution shell.

	Edited 10 × 10	Unedited 10 × 10	Edited 23 × 19
Data collection
Space group	H3	H3	P41212 or P43212
Unit-cell parameters (Å)	a = 39.5, c = 246.4	a = 49.0, c = 235.8	a = 62.5, c = 63.6
Resolution	29.92–1.35 (1.40–1.35)	23.38–2.85 (2.95–2.85)	36.29–2.80 (2.90–2.80)
Total reflections	122008	16052	16572
Unique reflections	30558	4798	3307
Redundancy	3.99 (1.78)	3.35 (3.67)	5.01 (4.82)
Completeness (%)	96.8 (77.4)	97.2 (99.8)	97.0 (92.7)
〈I/σ(I)〉	13.1 (2.2)	10.3 (1.9)	11.4 (2.2)
Rsym† (%)	6.3 (35.4)	6.1 (37.9)	9.9 (33.4)
Twinning fraction	0.38	0.41	None
Refinement statistics
Resolution	30.0–1.5
No. of atoms (RNA/water)	1257/26
Rwork‡/Rfree§ (%)	31.9/31.8
R.m.s.d. bonds (Å)	0.0038
R.m.s.d. angles (°)	0.94

^† R _sym = × 100.

^‡ R _work = × 100. R _work was calculated using 93% of the data.

^§ R _free is defined as the R _work calculated using 7% of the data selected randomly and excluded from the refinement.