Figure 2.

Overview of the general resistance mechanisms for Zn found in Gram-negative and -positive bacteria (Created with BioRender). In Gram negative and positive bacteria, general resistance mechanisms aid in efflux, sequestration, chelation, and metal uptake for their survival in toxic or scarce conditions. For the metal Zn, uptake in Gram positive bacteria from the outer environment is facilitated by P-type ATPase (ZosA), and Zn membrane transporters. For efflux of Zn ions out of the cell, CDF and RND efflux pumps (Czc determinants found in both Gram positive and negative bacteria), as well as CPx-type (CadA in Gram positive bacteria) and P-type ATPases (ZntA in both Gram positive and negative bacteria) are majorly involved. Moreover, intracellular or periplasmic proteins can bind to Zn inside the cell.