Based on the fit of the three domains of the barley SGT1 protein into the model of the SGT1 dimer, one can conclude that the TPR domains act as a hub with the CS-SGS domains protruding in the opposite directions. The superposition of the SGT1 monomer model obtained from GASBOR with the model of the SGT1 dimer clearly indicates a large dimerization interface. As previously shown, SAXS can help to predict the solution structure of a particle on the basis of ab initio methods. Moreover, using crystallographic and NMR structures, or structures obtained on the basis of bioinformatics tools, the macromolecular structure in solution can be proposed using experimental SAXS data and rigid body modeling. To confirm the barley SGT1 models obtained from ab initio modeling of low-resolution structures, we also applied rigid body modeling, using the program BUNCH from the ATSAS package. To perform rigid body modeling, we first SKF38393 HCl modeled SGT1 domains using the protein structure prediction servers QUARK and I-TASSER. In rigid body modeling, the flexible regions between the rigid domains were represented as dummy residues with no structural constraints. Additionally, no symmetry constraints were used in the calculations. The resulting model of the barley SGT1 monomer has an extended conformation, with rigid domains behaving similar to beads on a string. The variable regions VR1 and VR2 are disordered and adopt an extended conformation. The extended shape and long unfolded regions give the monomeric barley SGT1 a high degree of flexibility and dynamics, and, surprisingly, they do not cause aggregation. To check whether the dimeric form of SGT1 also adopts an extended and flexible conformation, the barley SGT1 dimer was modeled using the same method as in BUNCH; however, in this case, the method was implemented for multichain proteins in the program CORAL. For this procedure the contacts between the TPR domains were used as constraints to obtain more reliable results, and no symmetry constraints of the SGT1 dimer were assumed.As expected, the barley SGT1 dimer is also highly flexible, and has a dynamic L-Asarinin conformation with VR1 and VR2 unfolded. The dimerization only affects the TPR domains, which undergo oligomerization, but it does not influence the other parts of the protein.