OxyR controls magnetosome formation by regulating magnetosome island (MAI) genes, iron metabolism, and redox state.
Free Radic Biol Med
; 161: 272-282, 2020 12.
Article
em En
| MEDLINE
| ID: mdl-33075503
ABSTRACT
Magnetospirillum gryphiswaldense MSR-1 uses chains of magnetosomes, membrane-enveloped magnetite (Fe(II)Fe(III)2O4) nanocrystals, to align along magnetic field. The process of magnetosome biomineralization requires a precise biological control of redox conditions to maintain a balanced amounts of ferric and ferrous iron. Here, we identified functions of the global regulator OxyR (MGMSRv2_4250, OxyR-4250) in MSR-1 during magnetosome formation. OxyR deletion mutant ΔoxyR-4250 displayed reduced magnetic response, and increased levels of intracellular ROS (reactive oxygen species). OxyR-4250 protein upregulated expression of six antioxidant genes (ahpC1, ahpC2, katE, katG, sodB, trxA), four iron metabolism-related regulator genes (fur, irrA, irrB, irrC), a bacterioferritin gene (bfr), and a DNA protection gene (dps). OxyR-4250 was shown, for the first time, to directly regulate magnetosome island (MAI) genes mamGFDC, mamXY, and feoAB1 operons. Taken together, our findings indicate that OxyR-4250 helps maintain a proper redox environment for magnetosome formation by eliminating excess ROS, regulating iron homeostasis and participating in regulation of Fe2+/Fe3+ ratio within the magnetosome vesicle through regulating MAI genes.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Magnetospirillum
/
Magnetossomos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Free Radic Biol Med
Assunto da revista:
BIOQUIMICA
/
MEDICINA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
China