Table 1.

Cryo-EM data collection, refinement and validation statistics

	Mtb WhiB7-RPo (W-RPo) PDB ID 7KIF	Mtb WhiB7-RPc (W-RPc) PDB ID 7KIM	Mtb RPo PDB ID 7KIN
Data collection and processing
Magnification	105,000		105,000
Voltage (kV)	300		300
Electron exposure (e−/Å2)	66		64
Defocus range (μm)	1–2.1		0.8–2.2
Pixel size (Å)	1.1		1.1
Symmetry imposed	C1		C1
Initial particle images (no.)	4,349,833		2,362,200
Final particle images (no.)	87,743	32,172	296,097
Map resolution (Å) FSC threshold 0.143	2.94	3.38	2.74
Map resolution range (Å)	2.8–7	3.3–7.5	2.8–6.6
Refinement
Initial model used (PDB code)	6EDT	6EDT	6EDT
Model resolution range (Å)	2.8–7	3.3–7.5	2.8–6.6
Map sharpening B factor (A2)	70.5	52.8	89.9
Model composition
Non-hydrogen atoms	30,322	29,573	29,379
Protein residues	3592	3572	3509
Nucleic acid residues	118	90	103
Ligands	4 (SF4, 1 Mg2+, 2 Zn2+)	4 (SF4, 1 Mg2+, 2 Zn2+)	3 (Mg2+, 2 Zn2+)
B factors (A2)
Protein	104.46	167.51	100.97
Nucleic acid	221.97	265.08	191.21
Ligands	120.37	170.20	92.75
R.m.s. deviations
Bond lengths (Å)	0.009	0.008	0.016
Bond angles (°)	0.865	0.873	1.047
Validation
MolProbity score	2.3	2.53	2.2
Clashscore	4.33	7.46	3.35
Poor rotamers (%)	6.85	7.44	7.82
Ramachandran plota
Most favored (%)	84.2	82.8	87.1
Additional allowed (%)	15.4	17	12.5
Generously allowed (%)	0.3	0.2	0.3
Disallowed (%)	0	0	0

^aRamachandran plot parameters from PROCHECK