7RCJ

Crystal structure of ZnuA from Citrobacter koseri

Summary for 7RCJ

• Entry DOI: 10.2210/pdb7rcj/pdb
• Descriptor: High-affinity zinc uptake system protein ZnuA, ZINC ION, 6-tungstotellurate(VI) (3 entities in total)
• Functional Keywords: zinc, transport, solute binding protein, metal binding protein
• Biological source: Citrobacter koseri (strain ATCC BAA-895 / CDC 4225-83 / SGSC4696)
• Total number of polymer chains: 6
• Total formula weight: 211834.90

Authors

Yukl, E.T.,Yekwa, E.L. (deposition date: 2021-07-07, release date: 2022-05-18, Last modification date: 2024-10-30)

Primary citation

Yekwa, E.L.,Serrano, F.A.,Yukl, E.
Conformational flexibility in the zinc solute-binding protein ZnuA.
Acta Crystallogr.,Sect.F, 78:128-134, 2022

PubMed Abstract: Zinc is an essential metal for all kingdoms of life, making its transport across the cell membrane a critical function. In bacteria, high-affinity zinc import is accomplished by ATP-binding cassette (ABC) transporters, which rely on extracellular solute-binding proteins (SBPs) of cluster A-I to acquire the metal and deliver it to the membrane permease. These systems are important for survival and virulence, making them attractive targets for the development of novel antibiotics. Citrobacter koseri is an emerging pathogen with extensive antibiotic resistance. High-affinity zinc binding to the C. koseri cluster A-I SBP ZnuA has been characterized and the structure of the zinc-bound (holo) form has been determined by X-ray crystallography. Remarkably, despite 95% sequence identity to the ZnuA homologue from Salmonella enterica, C. koseri ZnuA exhibits a different zinc-coordination environment and a closed rather than an open conformation. Comparison with structures of another close ZnuA homologue from Escherichia coli suggests a surprisingly flexible conformational landscape that may be important for efficient zinc binding and/or delivery to the membrane permease.

PubMed: 35234138
DOI: 10.1107/S2053230X22001662

Experimental method

X-RAY DIFFRACTION (3.15 Å)