(Micro)organisms are exposed to fluctuating environmental conditions, and adaptation to stress is essential for survival. Increased osmolality (hypertonicity) causes outflow of water and loss of turgor and is dangerous if the cell is not capable of rapidly restoring its volume. The osmoregulatory adenosine triphosphate-binding cassette transporter OpuA restores the cell volume by accumulating large amounts of compatible solute. OpuA is gated by ionic strength and inhibited by the second messenger cyclic-di-AMP, a molecule recently shown to affect many cellular processes. Despite the master regulatory role of cyclic-di-AMP, structural and functional insights into how the second messenger regulates (transport) proteins on the molecular level are lacking. Here, we present high-resolution cryo-electron microscopy structures of OpuA and in vitro activity assays that show how the osmoregulator OpuA is activated by high ionic strength and how cyclic-di-AMP acts as a backstop to prevent unbridled uptake of compatible solutes.
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http://dx.doi.org/10.1126/sciadv.abd7697 | DOI Listing |
Int J Biol Macromol
December 2024
College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China; Department of Biological Systems Engineering, Washington State University, 213 L.J. Smith Hall, Pullman, WA 99164-6120, USA. Electronic address:
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View Article and Find Full Text PDFInt J Biol Macromol
December 2024
College of Biological Engineering, Sichuan University of Science & Engineering, Zigong 643000, China.
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View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
College of Physics, Qingdao University, Qingdao 266071, China. Electronic address:
The poly(vinylidene fluoride) (PVDF) has been deemed as an appealing matrix for solid polymer electrolytes due to its wide electrochemical window and excellent thermal stability. Further incorporation with garnet filler endows PVDF-based electrolyte with increased ionic conductivity and mechanical strength. However, the spontaneous formation of alkaline layer containing LiOH/LiCO on garnet surface cannot be neglected, concerning its low ionic conductivity combined with the destructive effect on electrochemical performance of PVDF-based composite electrolytes.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
School of Materials Science and Engineering, State Key Lab of Silicon and Advanced, Semiconductor Materials, Zhejiang University, Hangzhou 310027, PR China. Electronic address:
NaMnTi(PO) is a promising sodium-ion cathode material due to its relatively high specific capacity, excellent thermodynamic stability and low cost. However, unfavorable electron conductivity and slow kinetics limit its practical application. Here, a strategy of hetero and multivalent anion substitution is proposed to achieve high-rate performance and good capacity retention.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2024
College of Chemical Engineering, Hubei University of Arts and Science, Xiangyang 441053, Hubei Province, PR China; Hubei Longzhong Laboratory, Xiangyang 441000, Hubei, PR China. Electronic address:
The rapeseed meal, a type of residual by-product of rapeseed oil production was used as the precursor to prepare nitrogen self-doping carbon dots RM-CDs through an easy hydrothermal process. Thanks to the introduction of nitrogen element and oxygen-containing functional groups, RM-CDs had a fluorescence quantum yield of 18.6 %.
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