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Selection of Transporter-Targeted Inhibitory Nanobodies by Solid-Supported-Membrane SSM-Based Electrophysiology
Published on: May 3, 2021
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Structural basis of a microbial trimethylamine transporter.
Chao Gao1,2,3,4, Hai-Tao Ding5, Kang Li2,4
1State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China.
Mbio
|November 22, 2024
Summary
Researchers elucidated the structure of the trimethylamine (TMA) transporter TmaT, revealing its mechanism for importing TMA across cell membranes. This provides key insights into TMA transport in marine microbes and its implications for human health.
Area of Science:
- Structural biology
- Biochemistry
- Microbiology
Background:
- Trimethylamine (TMA) is a ubiquitous biogenic amine with implications in human cardiovascular health and microbial nutrient cycling.
- The marine bacterium TMA transporter, TmaT, is crucial for TMA utilization, but its structure and transport mechanism were previously unknown.
Purpose of the Study:
- To determine the high-resolution structure of TmaT and its complexes with TMA.
- To elucidate the molecular mechanism of TMA transport mediated by TmaT.
Main Methods:
- Cryo-electron microscopy (cryo-EM) was used to solve the structures of TmaT and TmaT-TMA complexes.
- Biochemical analyses were performed to investigate TMA binding and transport.
Main Results:
- TmaT functions as an Na+/TMA symporter with high specificity and affinity for TMA.
- The cryo-EM structures revealed a homotrimer structure with a 12-transmembrane helix monomer and a four-helix bundle forming the transport channel.
- TMA transport involves movement between distinct aromatic binding boxes within the transporter.
Conclusions:
- The study provides the first structural and mechanistic insights into TMA transport by TmaT.
- The findings advance the understanding of TMA uptake in marine microbes and its broader biological significance.
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