5mrw | pdb_00005mrw

Structure of the KdpFABC complex

spinqualitylabelsall models 5mrw, resolution 2.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5mrw is a 12 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: BOG, K, PX4 NonStd Res: SEP Activity: Potassium-transporting ATPase, with EC number 3.6.3.12 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [KDPF_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:23930894). This subunit may be involved in stabilization of the complex (PubMed:10608856). [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). [A0A085P4P2_ECOLX] 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. This subunit acts as a catalytic chaperone that increases the ATP-binding affinity of the ATP-hydrolyzing subunit KdpB by the formation of a transient KdpB/KdpC/ATP ternary complex.[HAMAP-Rule:MF_00276][SAAS:SAAS00702316] [KDPB_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 is responsible for energy coupling to the transport system (PubMed:16354672). Publication Abstract from PubMed Cellular potassium import systems play a fundamental role in osmoregulation, pH homeostasis and membrane potential in all domains of life. In bacteria, the kdp operon encodes a four-subunit potassium pump that maintains intracellular homeostasis, cell shape and turgor under conditions in which potassium is limiting. This membrane complex, called KdpFABC, has one channel-like subunit (KdpA) belonging to the superfamily of potassium transporters and another pump-like subunit (KdpB) belonging to the superfamily of P-type ATPases. Although there is considerable structural and functional information about members of both superfamilies, the mechanism by which uphill potassium transport through KdpA is coupled with ATP hydrolysis by KdpB remains poorly understood. Here we report the 2.9 A X-ray structure of the complete Escherichia coli KdpFABC complex with a potassium ion within the selectivity filter of KdpA and a water molecule at a canonical cation site in the transmembrane domain of KdpB. The structure also reveals two structural elements that appear to mediate the coupling between these two subunits. Specifically, a protein-embedded tunnel runs between these potassium and water sites and a helix controlling the cytoplasmic gate of KdpA is linked to the phosphorylation domain of KdpB. On the basis of these observations, we propose a mechanism that repurposes protein channel architecture for active transport across biomembranes. Crystal structure of the potassium-importing KdpFABC membrane complex.,Huang CS, Pedersen BP, Stokes DL Nature. 2017 Jun 29;546(7660):681-685. doi: 10.1038/nature22970. Epub 2017 Jun, 21. PMID:28636601 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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