6A83

Crystal structure of the C-terminal periplasmic domain of EcEptC from Escherichia coli complex with Zn

Summary for 6A83

• Entry DOI: 10.2210/pdb6a83/pdb
• Descriptor: Phosphoethanolamine transferase EptC, ZINC ION, SODIUM ION, ... (4 entities in total)
• Functional Keywords: phosphoethanolamine transferase, transferase
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 45624.92

Authors

Zhao, Y.Q.,Gu, Y.J.,Cheng, W. (deposition date: 2018-07-06, release date: 2018-12-26, Last modification date: 2023-11-22)

Primary citation

Zhao, Y.,Meng, Q.,Lai, Y.,Wang, L.,Zhou, D.,Dou, C.,Gu, Y.,Nie, C.,Wei, Y.,Cheng, W.
Structural and mechanistic insights into polymyxin resistance mediated by EptC originating from Escherichia coli.
FEBS J., 286:750-764, 2019

PubMed Abstract: Gram-negative bacteria defend against the toxicity of polymyxins by modifying their outer membrane lipopolysaccharide (LPS). This modification mainly occurs through the addition of cationic molecules such as phosphoethanolamine (PEA). EcEptC is a PEA transferase from Escherichia coli (E. coli). However, unlike its homologs CjEptC (Campylobacter jejuni) and MCR-1, EcEptC is unable to mediate polymyxin resistance when overexpressed in E. coli. Here, we report crystal structures of the C-terminal putative catalytic domain (EcEptCΔN, 205-577 aa) of EcEptC in apo and Zn -bound states at 2.10 and 2.60 Å, respectively. EcEptCΔN is arranged into an α-β-α fold and equipped with the zinc ion in a conserved mode. Coupled with isothermal titration calorimetry (ITC) data, we provide insights into the mechanism by which EcEptC recognizes Zn . Furthermore, structure comparison analysis indicated that disulfide bonds, which play a key role in polymyxin resistance, were absent in EcEptCΔN. Supported by structural and biochemical evidence, we reveal mechanistic implications for disulfide bonds in PEA transferase-mediated polymyxin resistance. Significantly, because the structural effects exhibited by disulfide bonds are absent in EcEptC, it is impossible for this protein to participate in polymyxin resistance in E. coli. DATABASE: Structural data are available in the PDB under the accession numbers 6A82 and 6A83. ENZYME: EC 2.7.8.43.

PubMed: 30537137
DOI: 10.1111/febs.14719

Experimental method

X-RAY DIFFRACTION (2.602 Å)