10-A cryoEM structure and molecular model of the Myriapod (Scutigera) 6x6mer hemocyanin: understanding a giant oxygen transport protein.

Oxygen transport in Myriapoda is maintained by a unique 6 × 6mer hemocyanin, that is, 36 subunits arranged as six hexamers (1 × 6mers). In the sluggish diplopod Spirostreptus, the 1 × 6mers seem to operate as almost or fully independent allosteric units (h ∼ 1.3; P50 ∼ 5 torr), whereas in the swift centipede Scutigera, they intensively cooperate allosterically (h ∼ 10; P50 ∼ 50 torr).