Table 1.

Crystallographic data collection, phasing and refinement

		Se–Met derivative
	‘Native'	Peak	Edge
A. Data collection and phasing statistics
Wavelength (Å)	0.928	0.97931	0.97941
Total no. of reflections	807 714	709 329	719 313
Resolution range (Å)	50–2.4	50–3.05
No. of unique reflections	34 814 (3445)	18 452 (1714)	17 729 (1653)
Rsym (last shell)	0.087 (0.33)	0.112 (0.455)	0.11 (0.446)
Completeness (%) (last shell)	98.7 (99.9)	99.7 (97.7)	99.6 (98.0)
I/σ(I)	34.0 (7.8)	18.0 (3.5)	19.9 (3.8)
No. of Se sites	N/A	8	8
Phasing power (anomalous acentrics)	N/A	1.567	—
Mean overall figure of merit
Centric	N/A	0.7562
Acentric	N/A	0.6127	—
B. Refinement statistics
Resolution range (Å)	50–2.4	50–3.05
No. of reflections used in refinement	33 075	31 321
Rcryst/Rfree	0.22/0.27	0.24/0.29
No. of atoms
Protein	4235	4297
DNA	608	673
Water	186	113
Average B factors (Å2)	28.3	37.6
R.m.s.d.
Bonds (Å)	0.0065	0.0071
Angles (deg)	1.37	1.33
aRsym=∑∣In−〈In〉/∑In over all h, where In is the intensity of the reflection h.
bRcryst/Rfree=∑∣∣Fo∣−∣Fc∣∣/∑∣Fo∣. Rfree was calculated with 5% of data excluded from refinement.