Ligand-rebinding kinetics of 2/2 hemoglobin from the Antarctic bacterium Pseudoalteromonas haloplanktis TAC125

► Hydrostatic high pressure indicates a flexible globin that allows structural changes. ► Slow geminate recombination illustrates a relatively slow internal ligand binding. ► Oxygen affinity similar to those of globin O2 carriers. ► Fast O2 reduction indicates a putative redox reaction associating diatomic ligands.