Skip to main content
. 2013 Dec 24;3:108. doi: 10.3389/fcimb.2013.00108

Figure 1.

Figure 1

Schematic diagram of transporters involved in zinc uptake. The bacterial outer membrane is thought to be permeable to hydrophilic solutes of <600 dalton (Nikaido and Vaara, 1985) and, therefore, zinc concentration in the periplasmic space is largely dependent on zinc availability in the environment. Under zinc replete conditions (left), the metal is imported through low affinity import systems, such as ZupT, and Zur inhibits the expression of the importer ZnuABC. Under conditions of zinc shortage (right), apoZur is unable to bind DNA and the high affinity zinc importer ZnuABC is expressed. Neisseria meningitidis expresses a Zur-regulated TonB-dependent outer membrane protein, ZnuD, involved in zinc uptake.