1ZLQ

Crystallographic and spectroscopic evidence for high affinity binding of Fe EDTA (H2O)- to the periplasmic nickel transporter NikA

Summary for 1ZLQ

• Entry DOI: 10.2210/pdb1zlq/pdb
• Descriptor: Nickel-binding periplasmic protein, FE (III) ION, ACETATE ION, ... (9 entities in total)
• Functional Keywords: nickel, edta, transport, bacteria, hydrolase
• Biological source: Escherichia coli
• Cellular location: Periplasm (Probable): P33590
• Total number of polymer chains: 2
• Total formula weight: 114837.09

Authors

Cherrier, M.V.,Martin, L.,Cavazza, C.,Jacquamet, L.,Lemaire, D.,Gaillard, J.,Fontecilla Camps, J.C. (deposition date: 2005-05-09, release date: 2005-08-02, Last modification date: 2024-12-25)

Primary citation

Cherrier, M.V.,Martin, L.,Cavazza, C.,Jacquamet, L.,Lemaire, D.,Gaillard, J.,Fontecilla Camps, J.C.
Crystallographic and Spectroscopic Evidence for High Affinity Binding of FeEDTA(H(2)O)(-) to the Periplasmic Nickel Transporter NikA
J.Am.Chem.Soc., 127:10075-10082, 2005

PubMed Abstract: Because nickel is both essential and toxic to a great variety of organisms, its detection and transport is highly regulated. In Escherichia coli and other related Gram-negative bacteria, high affinity nickel transport depends on proteins expressed by the nik operon. A central actor of this process is the periplasmic NikA transport protein. A previous structural report has proposed that nickel binds to NikA as a pentahydrate species. However, both stereochemical considerations and X-ray absorption spectroscopic results are incompatible with that interpretation. Here, we report the 1.8 A resolution structure of NikA and show that it binds FeEDTA(H2O)- with very high affinity. In addition, we provide crystallographic evidence that a metal-EDTA complex was also bound to the previously reported NikA structure. Our observations strongly suggest that nickel transport in E. coli requires the binding of this metal ion to a metallophore that bears significant resemblance to EDTA. They also provide a basis for the potential use of NikA in the bioremediation of toxic transition metals and the design of artificial metalloenzymes.

PubMed: 16011372
DOI: 10.1021/ja0518530

Experimental method

X-RAY DIFFRACTION (1.8 Å)