. Author manuscript; available in PMC: 2017 Nov 1.

Published in final edited form as: Nat Struct Mol Biol. 2017 May 1;24(6):507–514. doi: 10.1038/nsmb.3407

Table 1. EM data collection and refinement statistics.

	ecCTPS filament (EMD-8504, PDB 5U3C)	hCTPS1 filament (EMD- 8474 PDB 5U03)	ecCTPS tetramer (EMD- 8475 PDB 5U05)	ecCTPS-CC (products)(EMD-8513, PDB 5U6R	ecCTPS-CC (substrates)(EMD-8491)	ecCTPS-CC (apo)(EMD-8490)	hCTPS1-H355A tetramer (EMD- 8476)
Data collection
Microscope	Polara	TF20	TF20	TF20	TF20	TF20	Spirit
Voltage (kV)	300	200	200	200	200	200	120
Detector	K2 summit	K2 summit	K2 summit	K2 summit	K2 summit	K2 summit	Ultrascan CCD
Electron exposure (e–/Å²)	34	45	68	45	45	45	30
Pixel size (Å)	1.22	1.26	1.26	1.26	1.26	1.26	2.07
Reconstruction
Point group symmetry	D2	D2	D2	D2	D2	D2	D2
Refined helical symmetry	48.5°, 81.6 Å	60.6°, 104.1		48.2°, 82.1Å	50.6°, 83.5Å	48.2°, 82.3 Å
Particles	8622	24880	6407	31170	7135	13715	4413
Resolution (0.143 fsc) (Å)	4.6	6.1	7.9	5.7	8.6	7.6	17
Refinement
Initial model used (PDB code)	2AD5	2VO1, 2VKT	2AD5	2AD5
Model composition
Protein residues	534	559	534	534
Ligands	CTP, ADP, Mg	UTP, ATP, Mg		CTP, ADP, Mg
Validation
Clashscore	2	4	14	2
Poor rotamers (%)	0.1	0.2	0.1	0.1
Ramachandran plot
Favored (%)	94	96	94	94
Allowed (%)	4	4	4	4
Outliers (%)	1	1	1	1