5) Our structures combined with our analytical ultracentrifugation and EPR experiments allow us to propose a mechanism by which these oxygen protecting complexes and filaments form in oxidizing conditions, protecting MoFeP and FeP, and disassemble in reducing conditions.

3) We show that Shetna is capable of binding both the catalytic (MoFeP) and reductant (FeP) subunits, creating oxygen protecting complex. Fascinatingly, this complex is capable of forming higher order complexes and ultimately filaments!