To complement the homology model in Figure 1, the MV2-Eury DsrAB heterotetramer was modeled also using AF2 Multimer (37). In this case the Fe-S centers and siroheme moieties are not present in the modeled structure. Three models were obtained, with the highest confidence (highest pLDDT scores) found for model 3 (Figure 4, Figure S2). As can be seen in the model colored according to the pLDDT score (Figure 4, Figure S2), the only regions of the complex that were poorly predicted in the models were in subunit A, residues 50-62 and 397-300. The first region interacts with the DsrC subunit (Figure 1B), while the second corresponds to four residues at the end of the first β-strand in a β-sheet adjacent to the A-subunit ferredoxin domain. Alignment of the MV2-Eury AF2 model with the homology model shows reasonable agreement (Figure 4), although the heterodimers in the AF2 model are rotated with respect to each other around the central axis of the heterodimer interface. Other notable differences are the orientations of the side chains at central interface between heterodimers (Figure S3) and a different orientation of the extended C-terminal A subunit helices that contact the opposing subunits. Note that the orientation of this helix is different in the A. fulgidus and D. vulgaris structures as well. The region with the low pLDDT scores (residues 50-62 in the A subunit) in the AF2 model exhibits a similar configuration to that in the homology model (Figure S3) but is rotated away from the center of the protein.