Table 2. Data Collection, Refinement, and Model Statistics of MbtI-10, MbtI–Mg²⁺, and MbtI–Ba^2+a.

	MbtI-10	MbtI–Mg2+	MbtI–Ba2+
space group	P21	I422	P21
Unit–Cell Parameters
a, b, c (Å)	88.336, 111.687, 94.998	193.97, 193.97, 257.03	88.04, 116.90 94.09
α, β, γ (deg)	90, 92.67, 90	90, 90, 90	90, 91.60, 90
Diffraction Data
resolution range (Å)	111.69–2.09 (2.13–2.09)	154.83–2.11 (2.15–2.11)	43.63–1.80 (1.85–1.80)
wavelength (Å)	0.97856	0.98012	0.98012
no. unique reflections	108510 (5396)	131041 (6551)	173404 (11664)
multiplicity	7.0 (7.1)	27.0 (26.5)	6.8 (6.5)
completeness (%)	99.9 (99.9)	93.9 (85.6)	99.2 (90.3)
average I/σ(I)	8.0 (2.1)	17.7 (1.4)	14.6 (1.0)
Rpimb	0.063 (0.356)	0.028 (0.546)	0.030 (0595)
CC(1/2)	0.990 (0.803)	0.998 (0.534)	0.999 (0.622)
Refinement Statistics
Rworkc	0.208	0.195	0.196
Rfreec	0.240	0.217	0.214
No. of Non-H Atomsd
protein	12651	13151	13228
ligands	65	198	51
water	878	797	1351
Average B-Factorsd
protein	43.33	51.97	35.98
ligands	56.33	89.33	43.89
water	44.14	53.14	42.82
RMS Deviationsd
bonds (Å)	0.012	0.012	0.012
angles (deg)	1.45	1.50	1.45
molprobity clashscored	3.13	2.90	1.51
Ramachandran outliersd (%)	0.00	0.00	0.00
Ramachandran favouredd (%)	98.98	98.34	98.80
rotamer outliersd (%)	1.09	1.11	1.11
C-β outliersd (%)	0.00	0.00	0.00
PDB code	6ZA4	6ZA5	6ZA6

^aData were indexed and scaled with XDSME (MbtI–Ba²⁺) or autoPROC (MbtI-10 and MbtI–Mg²⁺), applying, in the latter case, an anisotropic resolution cut-off via STARANISO as implemented in autoPROC.³⁰

^bR_pim = Σh[1/(/n_h – 1)]^1/2Σi|⟨I_h⟩I_h,i|/ΣhΣiI_h,i, where I_h is the intensity of the unique reflection h, whereas I_i is the intensity of each of its symmetry-equivalent reflections. CC(1/2) according to Karplus.³⁹

^cR_work = Σ||F_o| – |F_c||/Σ|F_o|, where F_o and F_c are the observed and calculated structure factor amplitudes. Five percent of the reflections were reserved for the calculation of R_free.

^dCalculated with phenix.validate.³⁷