Table 1.

Crystallographic data collection and refinement statistics.

Table S1: Crystallographic Statistics
Structure	Native	KI derivative	Hydroxyurea	Acetamide	Formamide
Data collection
Cell dimensions (Å)	a = 79.6 b = 81.9 c = 94.5	a = 79.7 b = 82.5 c = 94.1	a = 79.6 b = 81.5 c = 94.6	a = 79.6 b = 82.0 c = 94.1	a = 79.6 b = 81.7 c = 94.5
Total Reflections	2151808	254955	653922	883763	596495
Unique Reflections	126318	33665	113775	107983	92912
Resolutiona (Å)	50–1.38 (1.4–1.38)	50–2.12 (2.20–2.12)	50–1.42 (1.45–1.42)	50–1.40 (1.43–1.40)	50–1.42 (1.45–1.42)
Rmergea,b	0.071 (0.49)	0.083 (0.436)	0.062 (0.394)	0.044 (0.517)	0.052 (0.302)
I/σ(I)a	30.4 (3.7)	13.7 (2.8)	18.4 (2.0)	29.0 (2.5)	23.3 (2.7)
Completenessa (%)	99.4 (98.3)	93.6 (92.5)	97.6 (91.5)	88.7 (89.3)	79.6 (80.0)
Redundancya	8.6 (6.6)	3.3 (3.3)	3.5 (2.6)	4.0 (3.9)	4.2 (2.8)
Refinement
Space Group	P212121		P212121	P212121	P212121
Resolution (Å)	47.3–1.38		48.8–1.42	48.8–1.40	48.8–1.42
Rworkc	12.3		13.3	13.8	13.9
Rfree	14.6		15.7	16.2	16.5
Rfactor (all data)	12.5		13.4	13.9	14.0
Number of moleculesd	2		2	2	2
Number of protein atomsd	2690		2664	2583	2535
Number of solvent atomsd	575		473	453	428
Average B factors
(Å2)	18.3		17.2	17.1	16.7
Protein atoms	15.4		15.3	15.3	15.0
Solvent atoms	29.8		27.4	26.9	27.0
Rmsd bond lengths (Å)	0.02		0.02	0.02	0.02
Rmsd bond angles (deg)	1.5		1.6	1.5	1.5

^aThe values in parentheses indicate statistics for the highest resolution shell.

^bR_merge = Σ|I − <I>|/Σ<I>, where I is the observed intensity and <I> is the average intensity from multiple observations of symmetry-related reflections.

^cR = Σ||F_o| − |F_c||/Σ|F_o|, where F_o and F_c are the observed and calculated structure amplitudes, respectively.

^dPer asymmetric unit.