Fig. 2. ScATE1 binds a [2Fe-2S]²⁺ cluster when purified under oxic conditions.

a Photographs of plastic tubes containing purified ScATE1 (brown, left) and buffer (colorless, right) suggest the presence of an [Fe-S] cluster. b Features of the visible electronic absorption spectrum of ScATE1 isolated under oxic conditions indicate the presence of a [2Fe-2S]²⁺ cluster. Inset: expanded absorption spectrum showing both UV and visible regions. c The Fe XANES of ScATE1 isolated under oxic conditions. Inset: expanded pre-edge feature of the 1s→3d transition at 7112.5 eV, consistent with tetrahedral Fe³⁺ sites. d, e EXAFS of ScATE1 isolated under oxic conditions. The Fourier transformed data (d) and raw EXAFS (e) are consistent with the presence of a [2Fe-2S]²⁺ cluster. The black traces represent the experimental data, while the red traces represent the EXCURVE-fitted data. 1 Å = 0.1 nm. Source data are provided as a Source Data file.