9.A.10 The Iron/Lead Transporter (ILT) Superfamily

The ILT superfamily includes two families, the iron-transporting OFeT family and the lead-transporting PbrT family (see below). All sequenced homologues of the ILT superfamily have been multiply aligned, and conserved motifs, including fully conserved acidic residues in putative transmembrane segments (TMSs) 1 and 4, previously implicated in heavy metal binding, have been identified (Debut et al., 2006). Topological analyses confirmed the presence of 7 conserved TMSs in a 3 + 3 + 1 arrangement where the two 3 TMS elements are internally repeated. Phylogenetic analyses revealed the presence of several sequence divergent clusters of orthologous proteins that group roughly according to the phylogenes of the organisms of origin (Debut et al., 2006).