5L8G: Crystal structure of Rhodospirillum rubrum Rru_A0973 mutant H65A

Ferritins are ubiquitous proteins that oxidise and store iron within a protein shell to protect cells from oxidative damage. We have characterized the structure and function of a new member of the ferritin superfamily that is sequestered within an encapsulin capsid. We show that this encapsulated ferritin (EncFtn) has two main alpha helices, which assemble in a metal dependent manner to form a ferroxidase center at a dimer interface. EncFtn adopts an open decameric structure that is topologically distinct from other ferritins. While EncFtn acts as a ferroxidase, it cannot mineralize iron. Conversely, the encapsulin shell associates with iron, but is not enzymatically active, and we demonstrate that EncFtn must be housed within the encapsulin for iron storage. This encapsulin nanocompartment is widely distributed in bacteria and archaea and represents a distinct class of iron storage system, where the oxidation and mineralization of iron are distributed between two proteins.
PDB ID: 5L8GDownload
MMDB ID: 142670
PDB Deposition Date: 2016/6/7
Updated in MMDB: 2016/10
Experimental Method:
x-ray diffraction
Resolution: 2.974  Å
Source Organism:
Similar Structures:
Biological Unit for 5L8G: decameric; determined by author
Molecular Components in 5L8G
Label Count Molecule
Proteins (10 molecules)
Uncharacterized Protein
Molecule annotation
Chemicals (27 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB