Identification of an iron permease, cFTR1, in cyanobacteria involved in the iron reduction/re-oxidation uptake pathway.
Environ Microbiol
; 18(12): 5005-5017, 2016 12.
Article
en En
| MEDLINE
| ID: mdl-27450384
Cyanobacteria are globally important primary producers and abundant in many iron-limited aquatic environments. The ways in which they take up iron are largely unknown, but reduction of Fe3+ is an important step in the process. Here we report a special iron permease in Synechocystis, cFTR1, that is required for Fe3+ uptake following Fe2+ re-oxidation. The expression of cFTR1 is induced by iron starvation, and a mutant lacking the gene is abnormally sensitive to iron starvation. The cFTR1 protein localizes to the plasma membrane and contains the iron-binding motif "REXXE". Point-directed mutagenesis of the REXXE motif results in a sensitivity to Fe-deficiency. Measurements of iron (55 Fe) uptake rate show that cFTR1 takes up Fe3+ rather than Fe2+ . The function of cFTR1 in Synechocystis could be genetically complemented by the iron permease, Ftr1p, of Saccharomyces cerevisiae, that is known to transport Fe3+ produced by the oxidation of Fe2+ via a multicopper oxidase. Unlike yeast Ftr1p, cyanobacterial cFTR1 probably obtains Fe3+ primarily from the oxidation of Fe2+ by oxygen. Growth assays show that the cFTR1 is required during oxygenic, photoautotrophic growth but not when oxygen production is inhibited during photoheterotrophic growth. In cyanobacteria, iron reduction/re-oxidation uptake pathway may represent their adaptation to oxygenated environments.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Bacterianas
/
Synechocystis
/
Hierro
Tipo de estudio:
Diagnostic_studies
Idioma:
En
Revista:
Environ Microbiol
Asunto de la revista:
MICROBIOLOGIA
/
SAUDE AMBIENTAL
Año:
2016
Tipo del documento:
Article
Pais de publicación:
Reino Unido