Preferred MRT polypeptides are capable of, for example, transporting metals, e.g., Fe, e.g., Fe, Cd, Co, {HEAD ~ Mn}, Pb, {TAIL ~ Hg} and Zn 
Preferred MRT polypeptides are capable of , for example , transporting metals , e.g. , Fe , e.g. , Fe , Cd , Co , { HEAD ~ Mn } , Pb , { TAIL ~ Hg } and Zn
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH