1zlq

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Revision as of 05:24, 21 November 2007

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spinqualitylabelsall models 1zlq, resolution 1.8Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

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

Overview

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.

About this Structure

1ZLQ is a Single protein structure of sequence from Escherichia coli with FE, ACT, SO4, CL, EDT, DTT and GOL as ligands. Active as Nickel-transporting ATPase, with EC number 3.6.3.24 Full crystallographic information is available from OCA.

Reference

Crystallographic and spectroscopic evidence for high affinity binding of FeEDTA(H2O)- to the periplasmic nickel transporter NikA., Cherrier MV, Martin L, Cavazza C, Jacquamet L, Lemaire D, Gaillard J, Fontecilla-Camps JC, J Am Chem Soc. 2005 Jul 20;127(28):10075-82. PMID:16011372

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