Fig. 7. Concentration-dependent nonamerization of YscV_C.

For comparability, absorbances were normalized to the highest peak. From top to bottom: YscV_C, a ternary complex of YscV_C co-expressed with YscX₅₀ and His₆-YscY, and the same ternary complex but with full-length YscX (YscX_fl) were loaded at 2.5 µM (pink) to 100 µM (blue) onto a Superdex 200 column. For reference, the expected retention volumes for the monomeric species (or 1:1:1 heterotrimer) and nonameric species (assuming 9:9:9 stoichiometry and a globular shape) are shown as dashed gray lines. The weak auto-nonamerization of YscV_C is enhanced by the presence of YscX₅₀ but severely impeded by full-length YscX. Experiments were performed three times with consistent results.