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Title | Cryo-EM structures of pentameric autoinducer-2 exporter from Escherichia coli reveal its transport mechanism. |
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Journal, issue, pages | EMBO J, Vol. 41, Issue 18, Page e109990, Year 2022 |
Publish date | Sep 15, 2022 |
Authors | Radhika Khera / Ahmad R Mehdipour / Jani R Bolla / Joerg Kahnt / Sonja Welsch / Ulrich Ermler / Cornelia Muenke / Carol V Robinson / Gerhard Hummer / Hao Xie / Hartmut Michel / |
PubMed Abstract | 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 ...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. |
External links | EMBO J / PubMed:35698912 / PubMed Central |
Methods | EM (single particle) |
Resolution | 2.8 - 3.3 Å |
Structure data | EMDB-12256, PDB-7nb6: EMDB-13057, PDB-7ot9: |
Source |
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Keywords | STRUCTURAL PROTEIN / cryo-EM / membrane protein / autoinducer-2 exporter / quorum sensing / pentamer / protein oligomerization / AI-2E / transporter |