Table S1.

Key statistics and software used for SAXS data collection, processing, analysis, and rigid-body refinement

SASBDP entry	SASDBZ7	SASDB28	SASDB38
Data-collection parameters	C1r2s2 (batch)	C1q (batch)	C1 (inline)
Instrument	ESERF BM29	ESRF BM29	Petra P12
Wavelength, Å	0.992	0.992	1.24
q range, Å−1	4.6⋅10−3 to 0.50 (0.25)*	3.6⋅10−3 to 0.50	2.2⋅10−3 to 0.48 (0.25)*
Exposure time per frame, s	2	2	1
No. of frames averaged	10	10	100
Concentration range, mg⋅ml−1	1.01–6.79	3.66	N/A
Temperature, K	277.15	277.15	293.15
Structural parameters
I(0) [from P(r)]	436	534	N/A
Rg, Å [from P(r)]	130	126.6	114.6
I(0) (from Guinier)	436 for 1.8 mg⋅ml−1	535	N/A
Rg, Å (from Guinier)	126 ± 3.0	126 ± 2	115 ± 1
Dmax, Å	450	450	365
Porod volume estimate, Å3	645 × 103	965 × 103	2,050 × 103
Dry volume calculated from sequence and glycans†, Å3	399 × 103	563 × 103	992 × 103
Molecular mass Mr [from I(0)]‡, kDa	332	407	N/A
Calculated monomeric Mr from sequence, O-linked glycans, N-linked glycans, hydroxylations, kDa	330	444	774
Software used
Data processing	PyFAI/EDNA	PyFAI/EDNA	SASFLOW
Ab initio analysis	N/A	N/A	DAMMIN
Validation and averaging	N/A	N/A	DAMAVER Suite
Rigid-body modeling	CORALXL	N/A	CORALXL
Computation of model intensities	CORALXL	N/A	CORALXL

^*The maximum q range used for rigid-body modeling is indicated in the parentheses.

^†The volume was calculated as M_r times 1.21 ų/Da for the protein component. A volume of 2,535 ų was used for an Asn-linked glycan and 361 ų for the O-linked Glc-Gal disaccharide on hydroxylated lysine.

^‡Using BSA with I(0) = 94.52 and Mw = 72 kDa as a standard.