Chiang, W.T., Chang, Y.-K., Hui, W.-H. et al. (16 more authors) (2024) Structural basis and synergism of ATP and Na+ activation in bacterial K+ uptake system KtrAB. Nature Communications, 15. 3850. ISSN 2041-1723
Abstract
The K+ uptake system KtrAB is essential for bacterial survival in low K+ environments. The activity of KtrAB is regulated by nucleotides and Na+. Previous studies proposed a putative gating mechanism of KtrB regulated by KtrA upon binding to ATP or ADP. However, how Na+ activates KtrAB and the Na+ binding site remain unknown. Here we present the cryo-EM structures of ATP- and ADP-bound KtrAB from Bacillus subtilis (BsKtrAB) both solved at 2.8 Å. A cryo-EM density at the intra-dimer interface of ATP-KtrA was identified as Na+, as supported by X-ray crystallography and ICP-MS. Thermostability assays and functional studies demonstrated that Na+ binding stabilizes the ATP-bound BsKtrAB complex and enhances its K+ flux activity. Comparing ATP- and ADP-BsKtrAB structures suggests that BsKtrB Arg417 and Phe91 serve as a channel gate. The synergism of ATP and Na+ in activating BsKtrAB is likely applicable to Na+-activated K+ channels in central nervous system.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Author(s) 2024. This is an open access article under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Biomedical Sciences (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 03 Sep 2024 12:06 |
Last Modified: | 03 Sep 2024 12:06 |
Status: | Published |
Publisher: | Springer Nature |
Identification Number: | 10.1038/s41467-024-48057-y |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:216727 |