Data-collection parameters
Instrument:	ESRF BM29
Wavelength (Å)	0.99
q-range (Å-1)	0.0032 – 0.49
Sample-to-detector distance	2.864 m
Exposure time (sec)	1 per frame
Concentration range	n.a.
Temperature (K)	293
Detector	Pilatus 1M (Dectris)
Flux (photons/s)	1 × 1012
Beam size (µm2)	700 × 700
Structural parameters for D5323-785, SEC
I0 (cm-1) [from Guinier]	0.0237
Rg (Å) [from Guinier]	48
qminRg – qmaxRg used for Guinier	0.77 - 1.24
Dmax (Å) [from p(r) ]	145
q-range used for p(r) (Å-1)	0.02 - 0.17
Porod volume Vp (Å3) [from Scatter]	(570 ± 5) × 103
Molecular mass Mr (kDa) [from Vp]	345
Calculated monomeric Mr from sequence (kDa)	321
Structural parameters for D5323-785, IEC
I0 (cm-1) [from Guinier]	0.386
Rg (Å) [from Guinier]	46.5 ± 0.1
qminRg – qmaxRg used for Guinier	0.44 - 1.29
Dmax (Å) [from p(r) ]	120
q-range used for p(r) (Å-1)	0.03 - 0.18
Porod volume Vp (Å3) [from Scatter]	(577 ± 5) × 103
Molecular mass Mr (kDa) [from Vp]	339
Calculated hexameric Mr from sequence (kDa)	321