Table 1.

Cryo-EM data collection, refinement, and validation statistics

	E2 (EMD-19167) (PDB 8RH4)	GABA + E2 Primed (EMD-19171) (PDB 8RH7)	GABA + E2 Desensitized (EMD-19172) (PDB 8RH8)	PS (EMD-19173) (PDB 8RH9)	GABA + PS (EMD-19175) (PDB 8RHG)
Data collection and processing
Magnification	130,000	130,000	130,000	130,000	130,000
Voltage (kV)	300	300	300	300	300
Electron exposure (e–/Å2)	41.58	41.58	41.58	44.61	44.38
Defocus range (μm)	− 0.8 to − 1.8	− 0.8 to − 1.8	− 0.8 to − 1.8	− 0.8 to − 1.8	− 0.8 to − 1.8
Pixel size (Å)	0.6725	0.6725	0.6725	0.6725	0.6725
Symmetry imposed	C5	C5	C5	C1	C1
Final particles	134,816	100,833	140,148	93,154	88,968
Map resolution (Å) FSC threshold	2.52 0.143	2.78 0.143	2.66 0.143	3.21 0.143	3.01 0.143
Map resolution range (Å)	2.3–2.7	2.6–3.0	2.5–2.9	3.0–3.8	2.9–3.7
Refinement
Initial model (PDB code)	8OQ6	8OQ6	8OP9	8OQ6	8OP9
Model resolution (Å) FSC threshold	2.7 0.5	2.9 0.5	2.8 0.5	3.3 0.5	3.3 0.5
Map sharpening B factor (Å2)	− 97.2	− 112.2	− 109.6	− 101.0	− 97.9
Model composition
Non-hydrogen atoms	14292	13866	14067	14247	13897
Protein residues	1660	1610	1645	1665	1650
Ligands	62	61	42	51	26
B factors (Å2)
Protein	25.67	34.71	41.36	88.77	94.92
Ligand	46.63	44.83	72.40	85.43	75.75
R.m.s. deviations
Bond lengths (Å)	0.010	0.005	0.007	0.003	0.003
Bond angles (°)	1.261	1.105	1.265	0.628	0.501
Validation
MolProbity score	1.10	1.47	0.94	1.38	1.28
Clashscore	2.05	3.48	1.58	4.71	5.10
Poor rotamers (%)	0.32	0.34	0.33	0.06	0.07
Ramachandran plot
Favored (%)	97.38	95.28	97.85	97.26	97.98
Allowed (%)	2.62	4.72	2.15	2.74	2.02
Disallowed (%)	0.00	0.00	0.00	0.00	0.00