Role of a 21-kDa iron-regulated protein IrpA in the uptake of ferri-exochelin by Mycobacterium smegmatis.
J Appl Microbiol
; 129(6): 1733-1743, 2020 Dec.
Article
en En
| MEDLINE
| ID: mdl-32472729
AIMS: To characterize the 21-kDa iron-regulated cell wall protein in Mycobacterium smegmatis co-expressed with the siderophores mycobactin, exochelin and carboxymycobactin upon iron limitation. METHODS AND RESULTS: Mycobacterium smegmatis, grown in the presence of 0·02 µg Fe ml-1 (low iron) produced high levels of all the three siderophores, which were repressed in bacteria supplemented with 8 µg Fe ml-1 (high iron). Exochelin, the major extracellular siderophore was the first to rise and was expressed at high levels during log phase of growth. Carboxymycobactin, a minor component in log phase iron-starved M. smegmatis continued to rise when cultured for longer periods, reaching levels greater than exochelin. Iron-starved bacteria expressed a 21-kDa iron-regulated protein (IrpA) that was identified as Clp protease subunit (MSMEG_3671) and characterized as a receptor for ferri-exochelin. CONCLUSIONS: Ferri-exochelin is the preferred siderophore in M. smegmatis and this ferri-exochelin: IrpA machinery is absent in Mycobacterium tuberculosis. SIGNIFICANCE AND IMPACT OF THE STUDY: Exochelin machinery is functional in M. smegmatis and the carboxymycobactin-mycobactin machinery is the sole iron uptake system in M. tuberculosis. The absence of the ferri-exochelin: IrpA system in the pathogen signifies the importance of the carboxymycobactin-mycobactin system machinery in M. tuberculosis.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Péptidos Cíclicos
/
Proteínas Bacterianas
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Compuestos Férricos
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Mycobacterium smegmatis
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Proteínas Reguladoras del Hierro
/
Hierro
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Appl Microbiol
Asunto de la revista:
MICROBIOLOGIA
Año:
2020
Tipo del documento:
Article
País de afiliación:
India