Fitting of model curves, based on crystallographic and docked structures, on the averaged frames for mG-Pk4 (panel A), mG-Pk3 (panel C) and mG-Pk2 (panel E). In panels B, D and F, the respective normalized fit residuals [(I(q)fit − I(q)expt)/s.d.expt] are reported (the dashed horizontal lines indicate the ±2 s.d. limits). The χrσ values [equation (12)] are also reported in the inside legends in panels A, C and E. (Panel G) The aldolase crystallographic tetramer (PDB code 1ado). (Panel H) The best mG-Pk3 SAXS single-fitting ClusPro aldolase octamer (model No. 17). (Panels I–K) CluspPro octamers Nos. 8, 14 and 25, respectively, whose 36:48:14% combination produces the overall best fit to the mG-Pk3 SAXS profile. (Panels L–O) The four ClusPro aldolase dodecamer models contributing most to the NNLS best reconstructed curve for the mG-Pk2 SAXS profile (L, No. 10, 22%; M, No. 29, 23%; N, No. 9, 16%; O, No. 25, 32%; model Nos. 13 and 27, not shown, contribute 5 and 2%, respectively). Model No. 25 (panel O) is the single best fitting model. In all panels, each aldolase monomer is colored differently, while to make a comparison easier the orientation of the starting tetramer (G) is the same in all higher-order complexes produced.