Figure 6

ARS-like segments in various IDHs. The AceK recognition segment (ARS) in E.coli IDH [22] and ARS-like region sequences and structures in other IDHs. S1-IDHs have at least five groups with different structures, three of which are structurally represented here. Cyanobacteria like Nostoc IDH_ANASP have the longest ARS-like sequence, which is not structurally resolved yet. The shortest S1-type, IDH_STRMU (Streptococcus mutans) may be NAD-dependent. S2-IDHs have conserved structure, represented by Pig PmIDH. The residues may differ, however, as the alignment between PmIDH and Mycobacterium tuberculosis IDH_MYCTU shows here. The MtIDH sequence has a stretch of glutamates (-EEE-) and is richer in acidic residues. The shortest length is seen TtIDH, as well as S3-IDHs. Image was made using Chimera [80] and Jalview [33].