Escherichia coli has an iron(II) transport system (feo) which may make an important contribution to the iron supply of the cell under anaerobic conditions [1]. FeoB has been identified as part of this transport system. FeoB is a large 700-800 amino acid integral membrane protein. The N-terminus has been previously erroneously described as being ATP-binding [1]. Recent work shows that it is similar to eukaryotic G-proteins and that it is a GTPase [2].

1: Characterization of the ferrous iron uptake system of Escherichia coli. Kammler M, Schon C, Hantke K; J Bacteriol 1993;175:6212-6219. PMID:8407793

2: The membrane protein FeoB contains an intramolecular G protein essential for Fe(II) uptake in bacteria. Marlovits TC, Haase W, Herrmann C, Aller SG, Unger VM; Proc Natl Acad Sci U S A 2002;99:16243-16248. PMID:12446835