On the mechanism of membrane transport of zinc ions by ZntB

Zinc is essential for all branches of life and is the second most abundant transition metal divalent cation in living organisms after iron. Since metal ions cannot be synthesized, all living organisms rely on membrane proteins to take up metal cations from the environment. However, in many cases an excess of metals is toxic, thus there must be also membrane proteins capable to expel unnecessary ions. To fully understand these processes of metal transport in and out the cell, it is essential to solve structures of the membrane proteins in the presence and absence of their substrates, and to characterize them biochemically to propose and validate their transport mechanism. This thesis contributes in the understanding on the transport of zinc, and several other metal ions, via ZntB and other members of the 2-TM-GxN family, which are present in every kingdom of life.