Fig. 6: The E2o/E1o domain boundary in OdhA.

a Superimposition of the E2o domain of OdhA (yellow) to the catalytic domain of C. glutamicum E2p (AceF; gray, PDB 6ZZI²⁰). Focus is on the amphipathic helix that marks the C-terminal boundary of the OdhA E2o domain, which shows the same relative position as the C-terminal helix in AceF. To note the presence of a structurally conserved phenylalanine residue (indicated) that, in both proteins, contributes to maintain the helix relative orientation through intramolecular interactions. Such orientation was shown to be key to the loss of high-order oligomerisation in actinobacterial E2p enzymes. b Sequence logo derived from a multiple sequence alignment of OdhA orthologues from representative members of the Actinobacteria phylum (see Supplementary Fig. 17). The logo is here limited to the OdhA residues surrounding the conserved Phe340.