Targeting the selectivity filter to drastically alter the activity and substrate spectrum of a promiscuous metal transporter.

d-Block metal transporters are attractive engineering targets for selectively enriching or excluding metals in living organisms. However, systematic efforts to engineer these transporters have been hindered by limited knowledge on the determinants of substrate specificity. Here, we applied a focused-screen approach to human ZIP8, a promiscuous d-block divalent metal transporter, by systematically changing the residues that form a proposed selectivity filter at the entrance of the transport pathway.

Targeting the selectivity filter to drastically alter the activity and substrate spectrum of a promiscuous metal transporter.

-Block metal transporters play a crucial role in maintaining the homeostasis of life-essential trace elements and are attractive targets for protein engineering aimed to selectively enriching or excluding metals in living organisms. However, systematic efforts to engineer these transporters have been hindered by limited understanding of their transport mechanism and substrate specificity. In this study, we applied a focused-screen approach to human ZIP8, a promiscuous -block divalent metal transporter, by systematically changing three key residues that form the selectivity filter at the entrance of the transport pathway.