Representative SSA (a and c) and SSF (b and d) spectra for the DB domain of ERα pre-treated with EDTA to strip divalent zinc ions (DB) and upon reconstitution with divalent ions of zinc (DB[Zn]), cadmium (DB[Cd]), mercury (DB[Hg]), cobalt (DB[Co]), barium (DB[Ba]), copper (DB[Cu]), iron (DB[Fe]), lead (DB[Pb]), manganese (DB[Mn]), nickel (DB[Ni]) and tin (DB[Sn]). Note that the spectra with divalent metal ions that can regenerate the DB domain with DNA-binding potential are presented in (a–b), while spectra for divalent metal ions that fail to do so in (c–d).