7ZRG image
Entry Detail
PDB ID:
7ZRG
EMDB ID:
Title:
Cryo-EM map of the WT KdpFABC complex in the E1_ATPearly conformation, under turnover conditions
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2022-05-04
Release Date:
2022-11-16
Method Details:
Experimental Method:
Resolution:
3.50 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Potassium-transporting ATPase potassium-binding subunit
Chain IDs:A
Chain Length:557
Number of Molecules:1
Biological Source:Escherichia coli
Polymer Type:polypeptide(L)
Description:Potassium-transporting ATPase ATP-binding subunit
Chain IDs:D (auth: B)
Chain Length:682
Number of Molecules:1
Biological Source:Escherichia coli
Polymer Type:polypeptide(L)
Description:Potassium-transporting ATPase KdpC subunit
Chain IDs:B (auth: C)
Chain Length:190
Number of Molecules:1
Biological Source:Escherichia coli
Polymer Type:polypeptide(L)
Description:Potassium-transporting ATPase KdpF subunit
Chain IDs:C (auth: D)
Chain Length:27
Number of Molecules:1
Biological Source:Escherichia coli
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
SEP D SER modified residue
Primary Citation
Inhibited KdpFABC transitions into an E1 off-cycle state.
Elife 11 ? ? (2022)
PMID: 36255052 DOI: 10.7554/eLife.80988

Abstact

KdpFABC is a high-affinity prokaryotic K+ uptake system that forms a functional chimera between a channel-like subunit (KdpA) and a P-type ATPase (KdpB). At high K+ levels, KdpFABC needs to be inhibited to prevent excessive K+ accumulation to the point of toxicity. This is achieved by a phosphorylation of the serine residue in the TGES162 motif in the A domain of the pump subunit KdpB (KdpBS162-P). Here, we explore the structural basis of inhibition by KdpBS162 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 KdpBS162 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.

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Primary Citation of related structures