9X0K
Cryo-EM Structure of Turbo sazae ferritin chain A
Summary for 9X0K
| Entry DOI | 10.2210/pdb9x0k/pdb |
| EMDB information | 66436 |
| Descriptor | TsFerA (1 entity in total) |
| Functional Keywords | apoferritin, ferroxidase, iron, oxidation, storage, 24-mer, metal binding, metal binding protein |
| Biological source | Turbo sazae |
| Total number of polymer chains | 24 |
| Total formula weight | 482458.08 |
| Authors | |
| Primary citation | Namikawa, Y.,Negishi, L.,Kurumizaka, H.,Suzuki, M. Identification, functional characterization, and cryo-EM structural analysis of novel ferritin subunits in Turbo sazae. Febs J., 2026 Cited by PubMed Abstract: Turbo sazae, an edible gastropod, accumulates high levels of iron in its digestive gland, and the molecular mechanism underlying this accumulation has remained elusive. This study identified the proteins responsible for the iron accumulation and characterized their function and structure. We isolated two novel ferritins, TsFerA and TsFerB, from the digestive gland using high-performance liquid chromatography and inductively coupled plasma mass spectrometry. Gene expression analyses revealed that both genes were specifically expressed in the digestive gland. Recombinant TsFerA (rTsFerA) possessed ferroxidase (EC1.16.3.1) activity, whereas recombinant TsFerB (rTsFerB) showed no such activity. This result indicated that rTsFerA functions as an H-chain-like subunit responsible for iron oxidation, while rTsFerB acts as an L-chain-like subunit involved in iron core nucleation. Furthermore, we determined the structures of rTsFerA and rTsFerB using cryo-electron microscopy, at a resolution of 2.19 and 2.17 Å, respectively. The protein structures revealed a conserved ferroxidase center in rTsFerA, whereas key catalytic residues were substituted in rTsFerB. These findings demonstrate that T. sazae utilizes a cooperative system composed of two functionally distinct ferritin subunits to efficiently and safely store iron. This work clarifies the molecular mechanisms of iron metabolism in marine organisms, particularly in gastropods, revealing an optimized strategy to cope with massive iron influx. PubMed: 42187216DOI: 10.1111/febs.70601 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.19 Å) |
Structure validation
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