Table 1. Data-collection and refinement statistics.

Values in parentheses are for the highest resolution shell.

	Apo (PDB entry 6ayy)	T84A (PDB entry 6ayv)	T84S (PDB entry 6ayu)
Wavelength (Å)	0.97856	0.97856	0.97872
Resolution range (Å)	19.68–2.60 (2.69–2.60)	38.77–2.30 (2.38–2.30)	37.78–2.20 (2.28–2.20)
Space group	P6122	P6122	P6122
Unit-cell parameters (Å, °)	a = b = 131.54, c = 144.35, α = β = 90, γ = 120	a = b = 131.24, c = 144.15, α = β = 90, γ = 120	a = b = 130.89, c = 142.85, α = β = 90, γ = 120
Total reflections	481839	1042914	406039
Unique reflections	23145 (2254)	33106 (3247)	37186 (3651)
Multiplicity	21.6 (22.1)	23.7 (21.4)	10.8 (10.6)
Completeness (%)	99.6 (99.6)	99.9 (100.0)	100.0 (100.0)
Mean I/σ(I)	44.8 (1.7)	55.0 (2.1)	35.7 (2.1)
Wilson B factor (Å2)	62.1	49.5	49.2
R merge †	0.079 (1.806)	0.125 (2.314)	0.082 (1.326)
R p.i.m.	0.017 (0.456)	0.026 (0.469)	0.025 (0.426)
CC1/2 (%)	95.2 (67.2)	97.4 (69.1)	94.8 (90.7)
Reflections used in refinement	23137 (2254)	33102 (3247)	37185 (3651)
Reflections used for R free	1116 (112)	1674 (137)	1831 (193)
R work ‡	0.211 (0.269)	0.190 (0.235)	0.224 (0.281)
R free §	0.265 (0.349)	0.247 (0.286)	0.258 (0.304)
No. of non-H atoms	4558	5079	4626
Root-mean-square deviations
Bond lengths (Å)	0.009	0.009	0.008
Bond angles (Å)	1.27	1.30	1.30
Ramachandran plot
Favored (%)	94.6	96.8	96.1
Allowed (%)	4.9	3.0	3.6
Outliers (%)	0.5	0.2	0.3
Rotamer outliers (%)	0.0	0.6	0.2
Clashscore	11.0	10.6	8.7
Average B factor (Å2)	68.3	58.5	58.2

^† R _merge = , where 〈I(hkl)〉 is the mean I(hkl) value for all symmetry-related observations of that reflection.

^‡ R _work = , where F _obs and F _calc are the observed and calculated structure-factor amplitudes, respectively.

^§ R _free is calculated using 5% of the total reflections, which were randomly selected and were not used in refinement.