Download MendeleyA short intrinsically disordered region at KtrB's N-terminus facilitates allosteric regulation of K + channel KtrAB.
Stautz, J., Griwatz, D., Kaltwasser, S., Mehdipour, A.R., Ketter, S., Thiel, C., Wunnicke, D., Schrecker, M., Mills, D.J., Hummer, G., Vonck, J., Hanelt, I.(2025) Nat Commun 16: 4252-4252
- PubMed: 40335548 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.1038/s41467-025-59546-z
- Primary Citation Related Structures:
7ZP9, 7ZPO, 7ZPR - PubMed Abstract:
K + homeostasis is crucial for bacterial survival. The bacterial K+ channel KtrAB is regulated by the binding of ADP and ATP to the cytosolic RCK subunits KtrA. While the ligand-induced conformational changes in KtrA are well described, the transmission to the gating regions within KtrB is not understood. Here, we present a cryo-EM structure of the ADP-bound, inactive KtrAB complex from Vibrio alginolyticus, which resolves part of KtrB's N termini. They are short intrinsically disordered regions (IDRs) located at the interface of KtrA and KtrB. We reveal that these IDRs play a decisive role in ATP-mediated channel opening, while the closed ADP-bound state does not depend on the N-termini. We propose an allosteric mechanism, in which ATP-induced conformational changes within KtrA trigger an interaction of KtrB's N-terminal IDRs with the membrane, stabilizing the active and conductive state of KtrAB.
- Institute of Biochemistry, Goethe University Frankfurt, Frankfurt am Main, Germany.
Organizational Affiliation:
