Magnetic field effects on the structure and molecular behavior of pigeon iron–sulfur protein

• Published in: Protein science 2022-06, Vol.31 (6), p.e4313-n/a
• Main Authors: Arai, Shigeki, Shimizu, Rumi, Adachi, Motoyasu, Hirai, Mitsuhiro
• Format: Article
• Language: English
• Subjects: Animals; Clusters; Columbidae - metabolism; Full‐length Paper; Full‐length Papers; Geomagnetic field; Homology; Iron; Iron-sulfur proteins; Iron-Sulfur Proteins - genetics; iron–sulfur cluster; Magnetic Fields; Magnetic properties; Magnetism; magnetoreception; Molecular structure; oligomer; Oligomerization; Oligomers; Pigeons; Protein Subunits - metabolism; Proteins; SAXS; SEC; Sulfur
• ISSN: 0961-8368; 1469-896X
• DOI: 10.1002/pro.4313

Pigeon iron–sulfur (Fe–S) cluster assembly 1 homolog (clISCA1) is a target protein for research into the biomagnetoreception mechanism, as the clCRY4/clISCA1 oligomer, a complex composed of the columnar clISCA1 oligomer and the magnetosensor candidate protein cryptochrome‐4 (clCRY4) oligomer, tends to orient itself along weak magnetic fields, such as geomagnetic fields, under blue light. To obtain insight into the magnetic orientation mechanism of the clCRY4/clISCA1 oligomer, we inspected magnetic field effects on the structure and molecular behavior of clISCA1 by small angle X‐ray scattering analysis. The results indicated that the clISCA1 protomer took the Fe–S cluster‐bound globular form and unbound rod‐like form. The globular clISCA1 protomer assembled to form columnar oligomers, which allowed for the binding of many Fe–S clusters at the interface between clISCA1 protomers. Moreover, the translational diffusion and the columnar oligomerization of clISCA1 were controlled by the external static magnetic field and Fe–S clusters bound to clISCA1. However, the columnar clISCA1 oligomer was not oriented along the external static magnetic field (~1 T) when clCRY4 was not bound to clISCA1. This result indicated that clCRY4 has a function to enhance the magnetic orientational property of clCRY4/clISCA1 oligomer.