Table 1. Data collection and refinement statistics.

	ScS1-ADP	ScS1-SO4
Data collection
Resolution range, Å	50.0-3.10	38.79-2.75
Unique reflections	21,662	31,951
Multiplicity	4.5	4.0
Average I/σ	27.2	20.5
Rsym, % (all data/outer shell)	10.2/39.3	4.8/38.5
Completeness, % (all data/outer shell)	89.4/78.8	88.0/81.8
Refinement
σ cutoff	0.0	2.0
Completeness in range, %	84.6	76.3
R factor, %	23.3	24.2
Rfree, % (5% partition)	26.9	28.6
Mean B-factor	80.5	57.1
rms deviations*
Bond lengths, Å	0.006	0.011
Bond angles,°	1.6	1.4
No. of protein atoms	8,578	8,661
No. of water atoms	1	95
No. of prosthetic atoms	33	8
Cross-validated coordinate error, ņ	0.47	0.5

The cell parameters of the two structures are as follows: ScS1-ADP, P2₁: a = 84.1 Å, b = 50.9 Å, c = 161.6 Å, α = 90.0°, β = 98.4°, and γ = 90.0°; ScS1-SO₄, P2₁: a = 83.6 Å, b = 51.1 Å, c = 162.3 Å, α = 90.0°, β = 98.0°, and γ = 90.0°. Eighty-two percent of the ScS1-SO₄ residues and 83% of the ScS1-ADP residues in the final models are in the most favored regions of the Ramachandran plot, with the rest in additionally allowed regions.

^*See ref. 46.

^†See refs. 26, 47, and 48.