Open AccessThe Mycobacterium tuberculosis High-Affinity Iron Importer, IrtA, Contains an FAD-Binding Domain
Author(s) -
Michelle B. Ryndak,
Shuishu Wang,
Issar Smith,
G. Marcela Rodríguez
Publication year - 2010
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.00223-09
Subject(s) - siderophore , biology , mycobacterium tuberculosis , biochemistry , bacteria , microbiology and biotechnology , tuberculosis , transporter , mycobacterium , iron deficiency , secretion , assimilation (phonology) , gene , genetics , medicine , pathology , anemia , linguistics , philosophy
Iron is an essential nutrient not freely available to microorganisms infecting mammals. To overcome iron deficiency, bacteria have evolved various strategies including the synthesis and secretion of high-affinity iron chelators known as siderophores. The siderophores produced and secreted byMycobacterium tuberculosis , exomycobactins, compete for iron with host iron-binding proteins and, together with the iron-regulated ABC transporter IrtAB, are required for the survival ofM. tuberculosis in iron deficient conditions and for normal replication in macrophages and in mice. This study further characterizes the role of IrtAB inM. tuberculosis iron acquisition. Our results demonstrate a role for IrtAB in iron import and show that the amino terminus domain of IrtA is a flavin-adenine dinucleotide-binding domain essential for iron acquisition. These results suggest a model in which the amino terminus of IrtA functions to couple iron transport and assimilation.