Fig. 5.

Analysis by SAXS. (A) Table summarizing molecular-weight calculations by size-exclusion chromatography and by SAXS. (B) Schematic drawing depicting the role of individual PUR repeats in the formation of PUR domains and Pur-α dimerization. (C) Scattering curve of Pur-α (I–II) and representative surface envelope calculated from SAXS measurements. (D) A fit of the crystal structure into the surface envelope of Pur-α (I–II) confirms the presence of intramolecular PUR domains in solution. (E) Scattering curve of Pur-α (I–III) and representative surface envelope calculated from SAXS measurements. These envelopes adopt a Z-like shape. (F) A fit of three PUR domains into the Z-like envelope is consistent with the presence of two intramolecular PUR domains and one intermolecular PUR domain (B). Structural models of Pur-α (I-II) were positioned manually in the envelopes to demonstrate the compatibility of envelopes with the size of PUR domains.