Table 1.

Statistics of cryo-EM data collection, refinement and validation.

Name	Hep-P1	Hep-P2	Hep-P3	Hep-P4	Apo-α-syn fibrilsa
PDB ID	7V4A	-	7V4B	7V4C	-
EMDB ID	EMD-31705	-	EMD-31706	EMD-31707	-
Data Collection
Pixel size (Å)	1.06	1.06	1.06	1.06	1.06
Defocus Range (μm)	−2.0 to −1.0	−2.0 to −1.0	−2.0 to −1.0	−2.0 to −1.0	−2.0 to −1.0
Voltage (kV)	300	300	300	300	300
Camera	K3	K3	K3	K3	K3
Microscope	Titan Krios	Titan Krios	Titan Krios	Titan Krios	Titan Krios
Exposure time (s/frame)	0.097	0.097	0.097	0.097	0.097
Number of frames	32	32	32	32	32
Total dose (e-/Å2)	55	55	55	55	55
Reconstruction
Micrographs	5473	5473	5473	5473	2321
Manually picked fibrils	92,118	92,118	92,118	92,118	38,830
Box size (pixel)	610	686	398	166	288
Inter-box distance (Å)	64.66	72.72	42.19	17.60	30.53
Segments extracted	83,529	291,650	262,084	188,227	583,394
Segments after Class2D	60,383	157,139	139,930	184,245	227,177
Segments after Class3D	20,111	94,743	47,063	38,286	105,423
Resolution (Å)	3.2	-	3.1	3.4	3.5
Map sharpening B-factor (Å2)	−95.39	-	−100.97	−100.35	−105.77
Half pitch (nm)	64.3	140.2	161.2	28.2	128.1
Helical rise (Å)	4.83	4.80	2.42	4.80	2.42
Helical twist (°)	−1.35	−0.62	179.73	−3.06	179.66
Atomic model
Non-hydrogen atoms	1653	-	3336	1287	-
Protein residues	240	-	480	186	-
Ligands	0	-	0	0	-
r.m.s.d. Bond lengths	0.002	-	0.006	0.008	-
r.m.s.d. Bond angles	0.518	-	0.597	0.745	-
All-atom clash score	8.54	-	15.32	11.74	-
Rotamer outliers	0.00%	-	0.00%	0.00%	-
Ramachandran Outliers	0.00%	-	0.00%	0.00%	-
Ramachandran Allowed	7.89%	-	13.16%	20.00%	-
Ramachandran Favored	92.11%	-	86.84%	80.00%	-

^aSame structure as a previously reported α-syn fibril structure (PDB ID: 6A6B)¹⁸ based on the density map.