Lookup NU author(s): Dr Emma Tarrant,
Dr Kevin Waldron,
Dr Jon Marles-Wright
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
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.
Author(s): He D, Hughes S, Vanden-Hehir S, Georgiev A, Altenbach K, Tarrant E, Mackay CL, Waldron KJ, Clarke DJ, Marles-Wright J
Publication type: Article
Publication status: Published
Print publication date: 05/09/2016
Online publication date: 16/08/2016
Acceptance date: 16/08/2016
Date deposited: 20/09/2016
ISSN (electronic): 2045-5267
Publisher: SAM Ltd.
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