Conformational ensembles of flexible multidomain proteins: How close are we to accurate and reliable predictions?

Rodriguez S Fournet A, Bartels S, Pajkos M, Clerc I, Carrière L, Thureau A, Montanier C, Dumon C, Allemand F, Cortés J, Bernadó P, Biophysical Journal (2026) DOI

SASD268 – Conformational ensembles of domain–linker–domain (DLD) protein chimera consisting of Glycosyl hydrolase and Carbohydrate binding module 18

Glycosyl hydrolase (GH) linked to a Carbohydrate-binding module (CBM) 18
MWexperimental 44 kDa
MWexpected 45 kDa
log I(s) 1.55×10-2 1.55×10-3 1.55×10-4 1.55×10-5
Glycosyl hydrolase (GH) linked to a Carbohydrate-binding module (CBM) 18 small angle scattering data  s, nm-1
ln I(s)
Glycosyl hydrolase (GH) linked to a Carbohydrate-binding module (CBM) 18 Guinier plot ln 1.55×10-2 Rg: 3.3 nm 0 (3.3 nm)-2 s2
(sRg)2I(s)/I(0)
Glycosyl hydrolase (GH) linked to a Carbohydrate-binding module (CBM) 18 Kratky plot 1.104 0 √3 sRg

Data validation


Fits and models


log I(s)
 s, nm-1
Conformational ensembles of domain–linker–domain (DLD) protein chimera consisting of Glycosyl hydrolase and Carbohydrate binding module 18 Rg histogram Rg, nm
Glycosyl hydrolase (GH) linked to a Carbohydrate-binding module (CBM) 18 MOMA FRESA model

Synchrotron SAXS data from solutions of Conformational ensembles of domain–linker–domain (DLD) protein chimera consisting of Glycosyl hydrolase and Carbohydrate binding module 18 in 50 mM Na-phosphate, 2 mM TCEP, pH 6 were collected on the SWING beam line at the SOLEIL storage ring (Saint-Aubin, France) using a Eiger 4M detector at a sample-detector distance of 2 m and at a wavelength of λ = 0.103 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). In-line size-exclusion chromatography (SEC) SAS was employed. The SEC parameters were as follows: A 50.00 μl sample at 8.4 mg/ml was injected at a 0.20 ml/min flow rate onto a column at 15°C. 630 successive 1 second frames were collected. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.

All 50 conformers were refined using MoMa FReSa, which is available as an additional zipped file.

Glycosyl hydrolase (GH) linked to a Carbohydrate-binding module (CBM) 18 (DLD18)
Mol. type   Protein
Organism   Chimera
Olig. state   Monomer
Mon. MW   44.7 kDa
Sequence   FASTA