7zrm | pdb_00007zrm

Cryo-EM map of the unphosphorylated KdpFABC complex in the E1-P_ADP conformation, under turnover conditions

spinqualitylabelsall models 7zrm, resolution 3.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7zrm is a 4 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ADP, K, MG, PHD Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function KDPA_ECOLI Part of the high-affinity ATP-driven potassium transport (or Kdp) system, which catalyzes the hydrolysis of ATP coupled with the electrogenic transport of potassium into the cytoplasm (PubMed:2849541, PubMed:8499455, PubMed:23930894). This subunit binds and transports the potassium across the cytoplasmic membrane (PubMed:7896809). Publication Abstract from PubMed KdpFABC is a high-affinity prokaryotic K<sup>+</sup> uptake system that forms a functional chimera between a channel-like subunit (KdpA) and a P-type ATPase (KdpB). At high K<sup>+</sup> levels, KdpFABC needs to be inhibited to prevent excessive K<sup>+</sup> accumulation to the point of toxicity. This is achieved by a phosphorylation of the serine residue in the TGES<sub>162</sub> motif in the A domain of the pump subunit KdpB (KdpB<sub>S162-P</sub>). Here, we explore the structural basis of inhibition by KdpB<sub>S162</sub> phosphorylation by determining the conformational landscape of KdpFABC under inhibiting and non-inhibiting conditions. Under turnover conditions, we identified a new inhibited KdpFABC state that we termed E1P tight, which is not part of the canonical Post-Albers transport cycle of P-type ATPases. It likely represents the biochemically described stalled E1P state adopted by KdpFABC upon KdpB<sub>S162</sub> phosphorylation. The E1P tight state exhibits a compact fold of the three cytoplasmic domains and is likely adopted when the transition from high-energy E1P states to E2P states is unsuccessful. This study represents a structural characterization of a biologically relevant off-cycle state in the P-type ATPase family and supports the emerging discussion of P-type ATPase regulation by such states. Inhibited KdpFABC transitions into an E1 off-cycle state.,Silberberg JM, Stock C, Hielkema L, Corey RA, Rheinberger J, Wunnicke D, Dubach VRA, Stansfeld PJ, Hanelt I, Paulino C Elife. 2022 Oct 18;11. pii: 80988. doi: 10.7554/eLife.80988. PMID:36255052 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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