Table 3 Cryo-EM data collection, refinement and validation statistics for LSU

Magnification

×165,000

×270,000

×270,000

×270,000

×105,000

Acceleration voltage (kV)

300

300

300

300

300

Electron exposure (e⁻/Ų)

11

6

6

6

25

Defocus range (μm)

−0.4 to −1.6

−0.4 to −1.0

−0.4 to 1.0

−0.4 to 1.0

−0.4 to −1.6

Pixel size (Å)

0.53

0.45

0.45

0.45

0.51

Symmetry imposed

C1

C1

C1

C1

C1

Initial particle images (no.)

754,663

219,953

757,044

464,723

2,146,827

Final particle images (no.)

514,855

179,724

419,159

275,137

1,301,160

Map resolution (Å)

1.86

1.83

1.64

1.98

1.65

 FSC threshold

0.143

0.143

0.143

0.143

0.143

Initial model used (PDB code)

7K00

7K00

7K00

7K00

7K00

Model resolution (masked, Å)

1.9

1.8

1.6

2.0

1.7

 FSC threshold

0.5

0.5

0.5

0.5

0.5

CC (mask)

0.76

0.85

0.80

0.84

0.77

CC (volume)

0.76

0.84

0.78

0.82

0.76

Map sharpening B factor (Ų)

−26.4

−18.0

−32.0

−22.0

−27.0

 Nonhydrogen atoms

86,648

92,830

88,150

94,181

87,899

 Protein residues

2,767

3,028

2,792

3,059

2,819

 RNA residues

2,724

2,872

2,738

2,867

2,743

 Waters

6,113

6,830

7,101

8,357

6,570

 Magnesium (MG)

246

220

260

254

219

 Potassium (K)

72

81

81

85

83

 Antibiotics*

6O1

G34, CA7 (8)

3QB, 6UQ

CLY, AM2

MUL, P8F (2)

 Protein

52.68

48.60

36.22

50.57

43.14

 RNA

57.51

44.15

41.64

45.61

40.17

 Ligand

51.25

58.66

23.33

37.21

31.73

 Water

41.80

38.02

30.76

42.29

36.51

 Bond lengths (Å)

0.009

0.008

0.008

0.008

0.008

 Bond angles (°)

1.547

1.556

1.531

1.579

1.585

 MolProbity score

0.90

0.82

0.67

0.85

0.74

 Clashscore

0.61

0.53

0.37

0.70

0.52

 Poor rotamers (%)

0.27

0.65

0.26

0.36

0.35

 Favored (%)

96.84

97.22

97.84

97.36

97.71

 Allowed (%)

3.05

2.74

2.16

2.58

2.29

 Disallowed (%)

0.11

0.03

0.00

0.07

0.00

 Ramachandran Z score

−1.28

−1.11

−0.57

−0.73

−0.49