Loss of conserved residues in Cyanidiophyceae ArsH and ArsM. The reference bacterial structures are shown for arsH and arsM, as are alignments and locations of conserved site changes in the structures that are present in the sequences of the proteins in G. yellowstonensis 5572, MtSh, and G. partita SAG21.92. These data suggest that the algal ars gene original functions may be compromised or lost (supplemental material). Made in biorender.