7ZRM

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

Summary for 7ZRM

• Entry DOI: 10.2210/pdb7zrm/pdb
• EMDB information: 14919
• Descriptor: Potassium-transporting ATPase potassium-binding subunit, Potassium-transporting ATPase KdpC subunit, Potassium-transporting ATPase KdpF subunit, ... (7 entities in total)
• Functional Keywords: p-type atpase, superfamily of k+ transporters (skt), potassium uptake system, membrane protein
• Biological source: Escherichia coli; More
• Total number of polymer chains: 4
• Total formula weight: 155331.95

Authors

Hielkema, L.,Stock, C.,Silberberg, J.M.,Corey, R.A.,Wunnicke, D.,Dubach, V.R.A.,Stansfeld, P.J.,Haenelt, I.,Paulino, C. (deposition date: 2022-05-04, release date: 2022-11-16)

Primary citation

Silberberg, J.M.,Stock, C.,Hielkema, L.,Corey, R.A.,Rheinberger, J.,Wunnicke, D.,Dubach, V.R.A.,Stansfeld, P.J.,Hanelt, I.,Paulino, C.
Inhibited KdpFABC transitions into an E1 off-cycle state.
Elife, 11:-, 2022

PubMed Abstract: 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 TGES motif in the A domain of the pump subunit KdpB (KdpB). Here, we explore the structural basis of inhibition by KdpB 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 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.

PubMed: 36255052
DOI: 10.7554/eLife.80988

Experimental method

ELECTRON MICROSCOPY (3.7 Å)