2.A.108.2.10
Dipartite iron uptake system, FetM (646 aas; 8 TMSs in a 1 +  7 TMS arrangement)/FetP (a periplasmic protein that enhances iron uptake by FetM) (Koch et al. 2011).  FetP binds Cu²⁺ and Mn²⁺ at two different sites, 1.3 Å apart, in this homodimeric protein, and the 3-d structure with Cu²⁺ bound to each of the two subunits reveals different geometries at the two sites. FetMP may be an iron permease with an iron scavenging function, and possibly also an iron reducing function (Koch et al. 2011).