Table 2 SAXS data collection, analysis, and modelling.

SASBDB code

SASDDB8

SASDDC8

Beamline

SWING, Soleil, Paris

Detector

PCCD170170 (AVIEX)

Beam geometry, mm²

1 × 0.5

Wavelength, Å

1.03

Mode

SEC

Column

4.6 × 300 mm Bio SEC-3

Initial concentration, mg/ml

13.7

9.0

Injected volume, µl

50

Flow rate, ml/min

0.2

Temperature, °C

15

Primary data reduction

FOXTROT

Data processing

Primus, Gnom^55,56

Ab initio analysis

DAMMIF³⁶

validation and averaging

DAMAVER⁵⁷

Modelling

EOM³⁸

Computation of model intensities

Crysol⁵⁵

3D graphics representation

Pymol

I(0)

0.037 ± 2.5e-5

0.039 ± 2.3e-5

R_g, Å

22.42 ± 0.03

31.75 ± 0.37

Q_min, 1/Å

0,0018

0,0025

qR_gmax

1.23

1.23

M from I(0), (ratio to predicted value)

1.30

1.05

I(0)

0.039 ± 0.91e-5

0.037 ± 0.27e-4

R_g, Å

22.43 ± 0.07

30.98 ± 0.03

D_max, Å

75

105

q range, 1/Å

0.0018–0.517

0.0025–0.517

M from I(0), (ratio to predicted value)

1.37

1.00

Porod volume estimate, ų (ratio V/calc. MW)

30128 (1.08)

60526 (1.08)

dry volume from sequence, ų

33777

67554

SAXS_MoW server, kDa

22.8

83

Scatter software, kDa

32.7

63.9

calculated from sequence, kDa

27.9

55.8

determined by MALS, kDa

27.5

55.5

q range for fitting, 1/Å

0.0018–0.517

0.0025–0.517

Symmetry and anisotropy assumptions

P1, none

P1, none

NSD (standard deviation), no. of clusters

1.036 (0.0022), 3

1.065 (0.0038), 4

χ² range

2.474–2.528

2.826–2.875

Constant adjustment to intenities

MW estimate (ratio to predicted value)

15.2 (0.54)

31.95 (0.57)

χ²

5.788

NA

number of representative structures

6

NA