Bacterial zinc uptake and regulators.
Many bacteria use an ABC transporter for high-affinity uptake of zinc with a cluster 9 solute-binding protein. Other members of this protein family transport manganese. At present, it is not always possible to distinguish zinc-specific and manganese-specific transporters on the basis of sequence analysis. Low-affinity ZIP-type zinc transporters in bacteria have also been identified. Most high-affinity zinc uptake systems are regulated by Zur proteins, which form at least three unrelated subgroups of the Fur protein family (regulators of iron transport). High-affinity transport of zinc out of the periplasmic space poses a problem to the cell because zinc is a cofactor of several periplasmic enzymes. Certain zinc-binding proteins in the periplasm might function as chaperones to supply these enzymes with zinc.
Hantke
Klaus
K
Mikrobiologie/Membranphysiologie, Universität Tübingen, Auf der Morgenstelle 28, D-72076 Tübingen, Germany. hantke@uni-tuebingen.de
D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000502:physiology; D000595:Amino Acid Sequence; D001419:Bacteria / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000502:physiology; D001692:Biological Transport; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D012097:Repressor Proteins / Q000502:physiology; D015032:Zinc / Q000378:metabolism*
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D012097:Repressor Proteins; D015032:Zinc