| 1. |
- Caretta, Martina Angela, et al.
(författare)
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Water remains a blind spot in climate change policies.
- 2022
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Ingår i: PLOS Water. - : Public Library of Science (PLoS). - 2767-3219. ; 1:12
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Tidskriftsartikel (refereegranskat)abstract
- For the first time in the latest Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), water has been the focus of dedicated chapters in both Working Group 1 (Chapter 8) and 2 (Chapter 4). Nevertheless, we argue here that water has not yet received the full attention it deserves from both scientists and policymakers for several reasons. Firstly, the historical focus on temperature change has been further increased with the use of global warming levels motivated by an aim to be consistent with current policy framings. Secondly, an increasing attention paid to extreme weather has sometimes overshadowed longer time-scale changes such as the aridification of an increasing fraction of arable land and the increasing variability of the water cycle from month to month, season to season, and year to year that also yield cascading impacts on all water use sectors. Thirdly, a stronger focus is needed on understanding the effectiveness of current and future adaptation strategies in reducing water-related climate risks. Finally, the role of water has not been adequately recognized in the assessment of mitigation strategies although the compliance with the Paris Agreement and the current pledges all require a massive deployment of land-based strategies whose feasibility and efficiency heavily depend on water resources. It is thus essential to develop a more integrated approach to water and climate change, that would allow scientists and policymakers to “close the loop” between mitigation options, water cycle changes, hydrological impacts and adaptation.
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| 2. |
- Currie, Michael J., et al.
(författare)
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Structural and biophysical analysis of a Haemophilus influenzae tripartite ATP-independent periplasmic (TRAP) transporter
- 2024
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Ingår i: ELIFE. - 2050-084X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Tripartite ATP-independent periplasmic (TRAP) transporters are secondary-active transporters that receive their substrates via a soluble-binding protein to move bioorganic acids across bacterial or archaeal cell membranes. Recent cryo-electron microscopy (cryo-EM) structures of TRAP transporters provide a broad framework to understand how they work, but the mechanistic details of transport are not yet defined. Here we report the cryo-EM structure of the Haemophilus influenzae N-acetylneuraminate TRAP transporter (HiSiaQM) at 2.99 & Aring; resolution (extending to 2.2 & Aring; at the core), revealing new features. The improved resolution (the previous HiSiaQM structure is 4.7 & Aring; resolution) permits accurate assignment of two Na+ sites and the architecture of the substrate-binding site, consistent with mutagenic and functional data. Moreover, rather than a monomer, the HiSiaQM structure is a homodimer. We observe lipids at the dimer interface, as well as a lipid trapped within the fusion that links the SiaQ and SiaM subunits. We show that the affinity (K-D) for the complex between the soluble HiSiaP protein and HiSiaQM is in the micromolar range and that a related SiaP can bind HiSiaQM. This work provides key data that enhances our understanding of the 'elevator-with-an-operator' mechanism of TRAP transporters.
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| 3. |
- Davies, James S., et al.
(författare)
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Selective Nutrient Transport in Bacteria : Multicomponent Transporter Systems Reign Supreme
- 2021
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Ingår i: Frontiers in Molecular Biosciences. - : Frontiers Media SA. - 2296-889X. ; 8
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Forskningsöversikt (refereegranskat)abstract
- Multicomponent transporters are used by bacteria to transport a wide range of nutrients. These systems use a substrate-binding protein to bind the nutrient with high affinity and then deliver it to a membrane-bound transporter for uptake. Nutrient uptake pathways are linked to the colonisation potential and pathogenicity of bacteria in humans and may be candidates for antimicrobial targeting. Here we review current research into bacterial multicomponent transport systems, with an emphasis on the interaction at the membrane, as well as new perspectives on the role of lipids and higher oligomers in these complex systems.
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| 4. |
- Davies, James S., et al.
(författare)
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Structure and mechanism of a tripartite ATP-independent periplasmic TRAP transporter
- 2023
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- In bacteria and archaea, tripartite ATP-independent periplasmic (TRAP) transporters uptake essential nutrients. TRAP transporters receive their substrates via a secreted soluble substrate-binding protein. How a sodium ion-driven secondary active transporter is strictly coupled to a substrate-binding protein is poorly understood. Here we report the cryo-EM structure of the sialic acid TRAP transporter SiaQM from Photobacterium profundum at 2.97 Å resolution. SiaM comprises a “transport” domain and a “scaffold” domain, with the transport domain consisting of helical hairpins as seen in the sodium ion-coupled elevator transporter VcINDY. The SiaQ protein forms intimate contacts with SiaM to extend the size of the scaffold domain, suggesting that TRAP transporters may operate as monomers, rather than the typically observed oligomers for elevator-type transporters. We identify the Na+ and sialic acid binding sites in SiaM and demonstrate a strict dependence on the substrate-binding protein SiaP for uptake. We report the SiaP crystal structure that, together with docking studies, suggest the molecular basis for how sialic acid is delivered to the SiaQM transporter complex. We thus propose a model for substrate transport by TRAP proteins, which we describe herein as an ‘elevator-with-an-operator’ mechanism.
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| 5. |
- Davies, James S., et al.
(författare)
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TRAPs : the 'elevator-with-an-operator' mechanism
- 2024
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Ingår i: Trends in Biochemical Sciences (TIBS). - 0968-0004 .- 1362-4326. ; 49:2, s. 134-144
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Forskningsöversikt (refereegranskat)abstract
- Tripartite ATP -independent periplasmic (TRAP) transporters are nutrient -uptake systems found in bacteria and archaea. These evolutionary divergent transporter systems couple a substrate -binding protein (SBP) to an elevator -type secondary transporter, which is a first -of -its -kind mechanism of transport. Here, we highlight breakthrough TRAP transporter structures and recent functional data that probe the mechanism of transport. Furthermore, we discuss recent structural and biophysical studies of the ion transporter superfamily (ITS) members and highlight mechanistic principles that are relevant for further exploration of the TRAP transporter system.
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