ArticlePLoS computational biology2020
Extracellular loops of BtuB facilitate transport of vitamin B12 through the outer membrane of E. coli.
Article in PLoS computational biology, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 20 papers.
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Who cites it
20 citing papers in PubMed, 30 citations in OpenAlex.
- Prolonged Stagnation Reduces Treated Wastewater Biostability by Altering Microbial Community: Insights From Metaproteomics.Environmental microbiology · 2026Article
- Advances in EPR Approaches for Studying Structural Properties of Membrane Proteins.Magnetic resonance in chemistry : MRC · 2026Review
- Vitamin B12 promotes cefiderocol resistance and small-colony variants in carbapenem-resistantmBio · 2026Article
- Spatial transcriptomics identifies novel Pseudomonas aeruginosa virulence factors.Cell genomics · 2025Article
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- Seeing is believing: Illuminating the Gram-negative outer membrane with molecular dynamics simulations.Current opinion in structural biology · 2024Review
- Recent Advances in Modeling Membrane β-Barrel Proteins Using Molecular Dynamics Simulations: From Their Lipid Environments to Their Assemblies.Methods in molecular biology (Clifton, N.J.) · 2024Article
- GdJournal of the American Chemical Society · 2023Article
- HDX-MS performed on BtuB inProceedings of the National Academy of Sciences of the United States of America · 2022Article
- What have molecular simulations contributed to understanding of Gram-negative bacterial cell envelopes?Microbiology (Reading, England) · 2022Review
- Article
- Structural and functional insights into colicin: a new paradigm in drug discovery.Archives of microbiology · 2021Review
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- Correction: Extracellular loops of BtuB facilitate transport of vitamin B12 through the outer membrane of E. coli.PLoS computational biology · 2021Article
- Remarkably coherent population structure for a dominant Antarctic Chlorobium species.Microbiome · 2021Article
- Vitamin BBiophysical journal · 2021Article
- Tight Adherence (Tad) Pilus Genes Indicate Putative Niche Differentiation in Phytoplankton Bloom AssociatedFrontiers in microbiology · 2021Article
- Guardians of the Cell: State-of-the-Art of Membrane Proteins from a Computational Point-of-View.Methods in molecular biology (Clifton, N.J.) · 2021Article
- Conformational Dynamics of the Extracellular Loop of BtuB in Whole Cells.Biophysical journal · 2020Article
- Application of TonB-Dependent Transporters in Vaccine Development of Gram-Negative Bacteria.Frontiers in cellular and infection microbiology · 2020Review
Corrections and comments
- Erratum issued
Authors and funding
2 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Vitamin B12 (or cobalamin) is an enzymatic cofactor essential both for mammals and bacteria. However, cobalamin can be synthesized only by few microorganisms so most bacteria need to take it up from the environment through the TonB-dependent transport system. The first stage of cobalamin import to E. coli cells occurs through the outer-membrane receptor called BtuB. Vitamin B12 binds with high affinity to the extracellular side of the BtuB protein. BtuB forms a β-barrel with inner luminal domain and extracellular loops. To mechanically allow for cobalamin passage, the luminal domain needs to partially unfold with the help of the inner-membrane TonB protein. However, the mechanism of cobalamin permeation is unknown. Using all-atom molecular dynamics, we simulated the transport of cobalamin through the BtuB receptor embedded in an asymmetric and heterogeneous E. coli outer-membrane. To enhance conformational sampling of the BtuB loops, we developed the Gaussian force-simulated annealing method (GF-SA) and coupled it with umbrella sampling. We found that cobalamin needs to rotate in order to permeate through BtuB. We showed that the mobility of BtuB extracellular loops is crucial for cobalamin binding and transport and resembles an induced-fit mechanism. Loop mobility depends not only on the position of cobalamin but also on the extension of luminal domain. We provided atomistic details of cobalamin transport through the BtuB receptor showing the essential role of the mobility of BtuB extracellular loops. A similar TonB-dependent transport system is used also by many other compounds, such as haem and siderophores, and importantly, can be hijacked by natural antibiotics. Our work could have implications for future delivery of antibiotics to bacteria using this transport system.
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