5A5V

A complex of the synthetic siderophore analogue Fe(III)-6-LICAM with the CeuE periplasmic protein from Campylobacter jejuni

Summary for 5A5V

• Entry DOI: 10.2210/pdb5a5v/pdb
• Descriptor: ENTEROCHELIN UPTAKE PERIPLASMIC BINDING PROTEIN, FE (III) ION, N,N'-hexane-1,4-diylbis(2,3-dihydroxybenzamide), ... (4 entities in total)
• Functional Keywords: transport protein, synthetic siderophore, ligand complex, periplasmic binding protein, tetradentate siderophores
• Biological source: CAMPYLOBACTER JEJUNI
• Total number of polymer chains: 1
• Total formula weight: 32372.08

Authors

Blagova, E.,Hughes, A.,Moroz, O.V.,Raines, D.J.,Wilde, E.J.,Turkenburg, J.P.,Duhme-Klair, A.-K.,Wilson, K.S. (deposition date: 2015-06-22, release date: 2016-07-06, Last modification date: 2024-01-10)

Primary citation

Wilde, E.J.,Hughes, A.,Blagova, E.V.,Moroz, O.V.,Thomas, R.P.,Turkenburg, J.P.,Raines, D.J.,Duhme-Klair, A.K.,Wilson, K.S.
Interactions of the periplasmic binding protein CeuE with Fe(III) n-LICAM(4-) siderophore analogues of varied linker length.
Sci Rep, 7:45941-45941, 2017

PubMed Abstract: Bacteria use siderophores to mediate the transport of essential Fe(III) into the cell. In Campylobacter jejuni the periplasmic binding protein CeuE, an integral part of the Fe(III) transport system, has adapted to bind tetradentate siderophores using a His and a Tyr side chain to complete the Fe(III) coordination. A series of tetradentate siderophore mimics was synthesized in which the length of the linker between the two iron-binding catecholamide units was increased from four carbon atoms (4-LICAM) to five, six and eight (5-, 6-, 8-LICAM, respectively). Co-crystal structures with CeuE showed that the inter-planar angles between the iron-binding catecholamide units in the 5-, 6- and 8-LICAM structures are very similar (111°, 110° and 110°) and allow for an optimum fit into the binding pocket of CeuE, the inter-planar angle in the structure of 4-LICAM is significantly smaller (97°) due to restrictions imposed by the shorter linker. Accordingly, the protein-binding affinity was found to be slightly higher for 5- compared to 4-LICAM but decreases for 6- and 8-LICAM. The optimum linker length of five matches that present in natural siderophores such as enterobactin and azotochelin. Site-directed mutagenesis was used to investigate the relative importance of the Fe(III)-coordinating residues H227 and Y288.

PubMed: 28383577
DOI: 10.1038/srep45941

Experimental method

X-RAY DIFFRACTION (2.04 Å)