The MgtE homolog FicI acts as a secondary ferrous iron importer in Shewanella oneidensis strain MR-1.

The MgtE homolog FicI acts as a secondary ferrous iron importer in Shewanella oneidensis strain MR-1. Appl Environ Microbiol. 2018 Jan 12;: Authors: Bennett BD, Redford KE, Gralnick JA Abstract The transport of metals into and out of cells is necessary for the maintenance of appropriate intracellular concentrations. Metals are needed for incorporation into metalloproteins but become toxic at higher concentrations. Many metal transport proteins have been discovered in bacteria, including the Mg2+ transporter-E (MgtE) family of passive Mg2+/Co2+ cation-selective channels. Low sequence identity exists between members of the MgtE family, indicating that substrate specificity may differ among MgtE transporters. Under anoxic conditions, dissimilatory metal-reducing bacteria such as Shewanella and Geobacter are exposed to high levels of soluble metals including Fe2+ and Mn2+ Here we characterize SO_3966, which encodes an MgtE homolog in Shewanella oneidensis that we name FicI (ferrous iron and cobalt importer) based on its role in maintaining metal homeostasis. A SO_3966 deletion mutant exhibits enhanced growth over wild-type under conditions with high Fe2+ or Co2+ concentrations but exhibits wild-type Mg2+ transport and retention phenotypes. Conversely, deleting feoB, which encodes an energy-dependent Fe2+ importer, confers a growth defect in low Fe2+ concentrations but not in high Fe2+ conditions. We propose that FicI represents a seconda...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research