Table S1.

X-ray diffraction data and refinement statistics for CysK/CdiA-CT^EC536 complexes

	CysK/CdiA-CT(H178A)EC536	CysK/CdiA-CT/CdiIEC536*
Space group	P41	C2221
Unit cell dimensions, Å	64.01 x 64.01 x 365.37	81.25 x 195.54 x 175.06
pH of crystallization condition	7.9	7.1
Protein concentration, mg/mL	20	20
Data collection
Wavelength, Å	1.0	0.9795
Resolution range	44.92–2.7	50–2.75
Unique reflections (total)	39,795 (303,136)	33,877 (483,433)
Completeness, %†	99.4	100.0
Redundancy†	12.8 (13.4)	14.3 (14.5)
Rmerge†‡	0.163 (0.734)	0.279 (1.159)
Rmeas†§	0.176 (0.791)	0.289 (1.201)
Rp.i.m.†¶	0.066 (0.293)	0.077 (0.314)
CC1/2†	0.996 (0.952)	0.995 (0.817)
I/σ†	19.96 (15.94)	10.41 (2.75)
NCS copies	2	2
Model refinement
Resolution range, Å	44.89–2.70	48.83–2.75
No. of reflections	39,640	36,673
No. of protein + ligand atoms	6,220	8,197
No. of water molecules	110	101
Missing residues	CdiA-CT:1–126 CysK:315–323	CdiA-CT:1–126 CysK:315–323 CdiI:125–128#
Rwork/Rfree, %||	20.2/22.4	19.4/24.2
rms deviations
Bond lengths, Å	0.009	0.011
Bond angles	1.225	1.072
Ramachandran plot
Most favorable region, %	97.08	95.83
Additional allowed region, %	2.92	3.90
Disallowed region	0	0.27
PDB ID code	5J43	5J5V

^*CdiA-CT/CdiI^EC536 complex is an SeMet derivative.

^†Statistics for the highest resolution shell are given in parentheses.

^‡R_merge = Σ_hklΣ_i |I_i(hkl) – (I(hkl))|/Σ_hklΣ_i I_i(hkl).

^§R_meas = Σ_hkl {N(hkl)/[N(hkl) – 1]}^1/2 Σ_i |I_i(hkl) – (I(hkl))|/Σ_hklΣ_i I_i(hkl).

^¶R_p.i.m (precision-indicating R_merge) = Σ_hkl {1/[N(hkl) – 1]} ^1/2 Σ_i |I_i(hkl) – (I(hkl))|/Σ_hklΣ_i I_i(hkl).

^#Missing residues for one CdiI protomer. The other CdiI protomer is missing only residue 128.

^||R_work = Σ|F_obs − F_calc|/ΣF_obs. R_free was computed identically except where all reflections belong to a test set of 5% randomly selected data.