Table II.
Comparison of Key Properties and Nature of the Active Sites of the Four Known LonP Structures
| hLonP | MjLonP | EcLonP | AfLonP | |
|---|---|---|---|---|
| PDB ID | 1xhk | 1rre | 1z0w and so forth | |
| LonA/B | A | B | A | B |
| Kingdom | Eukaryote | Archaea | Eubacteria | Archaea |
| Mutant | S to A | Some mutants | ||
| Oligomer | Monomer/dimer | Monomer (dimer not biological) | Hexamer | Monomers and hexamers |
| Active site 310 or β strand | 310 | 310 | β strand | β strand in all |
| Extended loop contact to adjacent subunit in hexamer | Cannot, as 310 | Cannot, as 310 | Yes | Yes, but different from EcLonP |
| Ser-Lys Dyad | Yes | Yes | Yes, mutant, modelled | No |
| Asp blocking Active Site | Yes | Yes | No | No |
| Lysine | Forms dyad, but buried by Asp | Forms dyad, but buried by Asp | Forms dyad | Accessible but no dyad |
| Active site | Closed form | Closed form, inactive | Open form, no Asp and Trp | No dyad, serine points away |
| Proposed activity based on conformation | Inactive | Inactive | Active with modeled serine | Inactive, serine in wrong place to form dyad |