7OT9 image
Entry Detail
PDB ID:
7OT9
EMDB ID:
Title:
Structure of the AI-2 exporter family protein YdiK from E. coli
Biological Source:
Host Organism:
PDB Version:
Deposition Date:
2021-06-09
Release Date:
2022-05-11
Method Details:
Experimental Method:
Resolution:
2.80 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:AI-2E member YdiK
Chain IDs:A, B (auth: E), C (auth: D), D (auth: C), E (auth: B)
Chain Length:370
Number of Molecules:5
Biological Source:Escherichia coli (strain K12)
Ligand Molecules
Primary Citation
Cryo-EM structures of pentameric autoinducer-2 exporter from Escherichia coli reveal its transport mechanism.
Embo J. 41 e109990 e109990 (2022)
PMID: 35698912 DOI: 10.15252/embj.2021109990

Abstact

Bacteria utilize small extracellular molecules to communicate in order to collectively coordinate their behaviors in response to the population density. Autoinducer-2 (AI-2), a universal molecule for both intra- and inter-species communication, is involved in the regulation of biofilm formation, virulence, motility, chemotaxis, and antibiotic resistance. While many studies have been devoted to understanding the biosynthesis and sensing of AI-2, very little information is available on its export. The protein TqsA from Escherichia coli, which belongs to the AI-2 exporter superfamily, has been shown to export AI-2. Here, we report the cryogenic electron microscopic structures of two AI-2 exporters (TqsA and YdiK) from E. coli at 3.35 Å and 2.80 Å resolutions, respectively. Our structures suggest that the AI-2 exporter exists as a homo-pentameric complex. In silico molecular docking and native mass spectrometry experiments were employed to demonstrate the interaction between AI-2 and TqsA, and the results highlight the functional importance of two helical hairpins in substrate binding. We propose that each monomer works as an independent functional unit utilizing an elevator-type transport mechanism.

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