2a29

The solution structure of the AMP-PNP bound nucleotide binding domain of KdpB

spinqualitylabelsall models 2a29 Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2a29 is a 1 chain structure with sequence from Escherichia coli. This structure supersedes the now removed PDB entry 1x6k. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR Ligands: ANP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function 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). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed P-type ATPases are ubiquitously abundant enzymes involved in active transport of charged residues across biological membranes. The KdpB subunit of the prokaryotic Kdp-ATPase (KdpFABC complex) shares characteristic regions of homology with class II-IV P-type ATPases and has been shown previously to be misgrouped as a class IA P-type ATPase. Here, we present the NMR structure of the AMP-PNP-bound nucleotide binding domain KdpBN of the Escherichia coli Kdp-ATPase at high resolution. The aromatic moiety of the nucleotide is clipped into the binding pocket by Phe(377) and Lys(395) via a pi-pi stacking and a cation-pi interaction, respectively. Charged residues at the outer rim of the binding pocket (Arg(317), Arg(382), Asp(399), and Glu(348)) stabilize and direct the triphosphate group via electrostatic attraction and repulsion toward the phosphorylation domain. The nucleotide binding mode was corroborated by the replacement of critical residues. The conservative mutation F377Y produced a high residual nucleotide binding capacity, whereas replacement by alanine resulted in low nucleotide binding capacities and a considerable loss of ATPase activity. Similarly, mutation K395A resulted in loss of ATPase activity and nucleotide binding affinity, even though the protein was properly folded. We present a schematic model of the nucleotide binding mode that allows for both high selectivity and a low nucleotide binding constant, necessary for the fast and effective turnover rate realized in the reaction cycle of the Kdp-ATPase. The holo-form of the nucleotide binding domain of the KdpFABC complex from Escherichia coli reveals a new binding mode.,Haupt M, Bramkamp M, Heller M, Coles M, Deckers-Hebestreit G, Herkenhoff-Hesselmann B, Altendorf K, Kessler H J Biol Chem. 2006 Apr 7;281(14):9641-9. Epub 2005 Dec 14. PMID:16354672 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also ATPase 3D structures

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