Extended Data Fig. 5: Sequence alignment and predicted structure of the most expressed multi-heme c-type cytochrome (DA_402) of Desulfurivibrio alkaliphilus during MISO.
From: Microbial iron oxide respiration coupled to sulfide oxidation
a, Pairwise alignment between DA_402 and the OmcS from G. sulfurreducens. Six out of seven predicted heme-binding motifs (CX2-5CH) are aligned with those in OmcS (labeled with numbers in circles). The seventh heme-binding motif lacks the paired histidine (blue color) for coordination of heme in the predicted structure of DA_402 and is therefore not considered in the following analysis. The leading signal peptide in DA_402 and OmcS is not shown. b, Predicted structure of DA_402 oligomer. DA_402 monomers are predicted to polymerize into a filament structure, similar to the cryo-EM structure of OmcS28. c, Structural comparison between DA_402 and OmcS. DA_402 shares significant topological similarity with OmcS, with a TM-score of 0.56 and DALI-score of 14.3. d, Spatial arrangement of six heme-binding sites in DA_402 (cyan). All heme-binding sites predicted in DA_402 align closely with those in OmcS (yellow), except the site 1’ showing shifted position. e, Predicted heme position of the heme-binding site 1’. Molecular docking analysis placed the heme (1’) in close proximity to the adjacent heme ②, with an iron-to-iron distance of 9.1 Å, comparable with the distance (12.5 Å) observed in OmcS.
