Structural insight into magnetochrome-mediated magnetite biomineralization.
Nature
; 502(7473): 681-4, 2013 Oct 31.
Article
em En
| MEDLINE
| ID: mdl-24097349
ABSTRACT
Magnetotactic bacteria align along the Earth's magnetic field using an organelle called the magnetosome, a biomineralized magnetite (Fe(II)Fe(III)2O4) or greigite (Fe(II)Fe(III)2S4) crystal embedded in a lipid vesicle. Although the need for both iron(II) and iron(III) is clear, little is known about the biological mechanisms controlling their ratio. Here we present the structure of the magnetosome-associated protein MamP and find that it is built on a unique arrangement of a self-plugged PDZ domain fused to two magnetochrome domains, defining a new class of c-type cytochrome exclusively found in magnetotactic bacteria. Mutational analysis, enzyme kinetics, co-crystallization with iron(II) and an in vitro MamP-assisted magnetite production assay establish MamP as an iron oxidase that contributes to the formation of iron(III) ferrihydrite eventually required for magnetite crystal growth in vivo. These results demonstrate the molecular mechanisms of iron management taking place inside the magnetosome and highlight the role of magnetochrome in iron biomineralization.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Bactérias
/
Óxido Ferroso-Férrico
/
Magnetossomos
Idioma:
En
Revista:
Nature
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
França