Bacterial ferrous iron transport: the Feo system

Abstract

To maintain iron homeostasis within the cell, bacteria have evolved various types of iron acquisition systems. Ferric iron (Fe(3+)) is the dominant species in an oxygenated environment, while ferrous iron (Fe(2+)) is more abundant under anaerobic conditions or at low pH. For organisms that must combat oxygen limitation for their everyday survival, pathways for the uptake of ferrous iron are essential. Several bacterial ferrous iron transport systems have been described; however, only the Feo system appears to be widely distributed and is exclusively dedicated to the transport of iron. In recent years, many studies have explored the role of the FeoB and FeoA proteins in ferrous iron transport and their contribution toward bacterial virulence. The three-dimensional structures for the Feo proteins have recently been determined and provide insight into the molecular details of the transport system. A highly select group of bacteria also express the FeoC protein from the same operon. This review will provide a comprehensive look at the structural and functional aspects of the Feo system. In addition, bioinformatics analyses of the feo operon and the Feo proteins have been performed to complement our understanding of this ubiquitous bacterial uptake system, providing a new outlook for future studies.

A preliminary study on the relationship between iron and black extrinsic tooth stain in children

“…Some of them participate in energy transformation, while some of them may participate in cell‐to‐cell communication between bacteria (Lau et al . ).…”

Identifying the Genes Responsible for Iron-Limited Condition in Riemerella anatipestifer CH-1 through RNA-Seq-Based Analysis

“…Once in the periplasm, Fe 2+ is taken across the inner membrane via a divalent metal uptake system, such as the Feo system of E. coli [25] and the Yfe system of Yersinia pestis [26]. In this study, the predicted genes feoB (B739_0594) and feoA (B739_0595), which encode an Fe 2+ transporter, were highly upregulated in the iron-limited condition, suggesting a role in the uptake of ferrous iron (Table 2).…”

Human calprotectin affects the redox speciation of iron

“…24 In many bacterial species, the Feo system ( feoABC ) mediates Fe(II) uptake. 25,26 Extracellular Fe(II) can be abundant under oxygen-limiting conditions, 27 and the Feo system has been implicated in the survival and virulence of bacterial pathogens that can inhabit low-oxygen microenvironments in the host, including Pseudomonas aerugionsa , 28,29 Helicobacter pylori , 30 Campylobacter jejuni , 31 Streptococcus suis, 32 and the obligate anaerobe Clostridium perfringens . 33 In addition to using the Fe(II) permease FeoB for Fe acquisition, the opportunistic human pathogen Pseudomonas aeruginosa produces and releases redox-cycling secondary metabolites named phenazines that reduce Fe(III) to Fe(II) in the extracellular environment and therefore proposed to facilitate Fe uptake via FeoB.…”