a, C98RhuA and b, F88/C98RhuA crystals. (left panels) The crystals were incubated in the presence of 20 or 30 mM βME and imaged by TEM at indicated times after addition of βME. (right panels) 125 μM C98RhuA or F88/C98RhuA were incubated under oxidative self-assembly conditions (in the presence of 10 mM βME at 4 °C with gentle shaking) and self-assembly was monitored by DLS at t = 0 (top), t = 3 days (center), and upon addition of 100 mM βME after self-assembly (bottom). c, (left panel) H63/H98RhuA crystals were incubated in the presence of 10 mM EDTA and imaged by TEM at 2 h after addition of EDTA. (right panels) 25 μM H63/H98RhuA was incubated under metal-mediated self-assembly conditions (in the presence of 200 μM ZnCl2 at 4 °C) and self-assembly was monitored by DLS at t = 0 (top), t = 3 days (center) and upon addition of 10 mM EDTA (bottom). Scale bars are 5 μm in all panels.