ZnuABC is a high-affinity transporter specialized for transporting zinc ions as part of a system for metal ion homeostasis in bacteria. The complex is a member of the ATP-binding cassette (ABC) transporter protein family. The transporter contains three protein components:[2][3]

High-affinity zinc uptake system protein ZnuA
The structure of ZnuA bound to zinc (gray sphere), with coordinating amino acids shown in white. From PDB: 2OSV​.[1]
Identifiers
OrganismEscherichia coli
SymbolZnuA
PDB2OSV
UniProtP39172
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StructuresSwiss-model
DomainsInterPro
High-affinity zinc uptake system membrane protein ZnuB
Identifiers
OrganismEscherichia coli
SymbolZnuB
UniProtP39832
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StructuresSwiss-model
DomainsInterPro
High-affinity zinc uptake system membrane protein ZnuC
Identifiers
OrganismEscherichia coli
SymbolZnuC
UniProtP0A9X1
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StructuresSwiss-model
DomainsInterPro

The expression of ZnuABC is regulated by the zinc uptake regulator (Zur) protein and is induced by conditions of zinc starvation. Because zinc is often a limiting factor in bacterial infections, some pathogenic bacteria are heavily dependent on ZnuABC to scavenge zinc from the environment in an animal host.[4]

The periplasmic protein ZnuA interacts with ZinT, another component of the regulon controlled by Zur, which is also involved in periplasmic zinc homeostasis.[4][5][6][7]

References edit

  1. ^ Li H, Jogl G (May 2007). "Crystal structure of the zinc-binding transport protein ZnuA from Escherichia coli reveals an unexpected variation in metal coordination". Journal of Molecular Biology. 368 (5): 1358–66. doi:10.1016/j.jmb.2007.02.107. PMID 17399739.
  2. ^ Patzer SI, Hantke K (June 1998). "The ZnuABC high-affinity zinc uptake system and its regulator Zur in Escherichia coli". Molecular Microbiology. 28 (6): 1199–210. doi:10.1046/j.1365-2958.1998.00883.x. PMID 9680209.
  3. ^ Yatsunyk LA, Easton JA, Kim LR, Sugarbaker SA, Bennett B, Breece RM, Vorontsov II, Tierney DL, Crowder MW, Rosenzweig AC (February 2008). "Structure and metal binding properties of ZnuA, a periplasmic zinc transporter from Escherichia coli". Journal of Biological Inorganic Chemistry. 13 (2): 271–88. doi:10.1007/s00775-007-0320-0. PMC 2630496. PMID 18027003.
  4. ^ a b Gabbianelli R, Scotti R, Ammendola S, Petrarca P, Nicolini L, Battistoni A (February 2011). "Role of ZnuABC and ZinT in Escherichia coli O157:H7 zinc acquisition and interaction with epithelial cells". BMC Microbiology. 11: 36. doi:10.1186/1471-2180-11-36. PMC 3053223. PMID 21338480.
  5. ^ Ilari A, Alaleona F, Tria G, Petrarca P, Battistoni A, Zamparelli C, Verzili D, Falconi M, Chiancone E (January 2014). "The Salmonella enterica ZinT structure, zinc affinity and interaction with the high-affinity uptake protein ZnuA provide insight into the management of periplasmic zinc" (PDF). Biochimica et Biophysica Acta (BBA) - General Subjects. 1840 (1): 535–44. doi:10.1016/j.bbagen.2013.10.010. hdl:2108/89370. PMID 24128931.
  6. ^ Petrarca P, Ammendola S, Pasquali P, Battistoni A (March 2010). "The Zur-regulated ZinT protein is an auxiliary component of the high-affinity ZnuABC zinc transporter that facilitates metal recruitment during severe zinc shortage". Journal of Bacteriology. 192 (6): 1553–64. doi:10.1128/jb.01310-09. PMC 2832539. PMID 20097857.
  7. ^ Blindauer CA (March 2015). "Advances in the molecular understanding of biological zinc transport" (PDF). Chemical Communications. 51 (22): 4544–63. doi:10.1039/c4cc10174j. PMID 25627157.