<taxon tax_id="562">Escherichia coli</taxon> has an iron(II) transport system (feo) which may make an important contribution to the iron supply of the cell under anaerobic conditions. FeoB has been identified as part of this transport system and may play a role in the transport of ferrous iron. FeoB is a large 700-800 amino acid integral membrane protein. The N terminus contains a P-loop motif suggesting that iron transport may be ATP dependent [<cite idref="PUB00009526"/>].