Structural highlights
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).[1] [2] [3] [4]
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 involved in the active transport of ions across biological membranes. The KdpFABC complex (P-type ATPase) of Escherichia coli is a high-affinity K+ uptake system that operates only when the cell experiences osmotic stress or K+ limitation. Here, we present the solution structure of the nucleotide binding domain of KdpB (backbone RMSD 0.17 A) and a model of the AMP-PNP binding mode based on intermolecular distance restraints. The calculated AMP-PNP binding mode shows the purine ring of the nucleotide to be "clipped" into the binding pocket via a pi-pi-interaction to F377 on one side and a cation-pi-interaction to K395 on the other. This binding mechanism seems to be conserved in all P-type ATPases, except the heavy metal transporting ATPases (type IB). Thus, we conclude that the Kdp-ATPase (currently type IA) is misgrouped and has more similarities to type III ATPases. The KdpB N-domain is the smallest and simplest known for a P-type ATPase, and represents a minimal example of this functional unit. No evidence of significant conformational changes was observed within the N-domain upon nucleotide binding, thus ruling out a role for ATP-induced conformational changes in the reaction cycle.
Inter-domain motions of the N-domain of the KdpFABC complex, a P-type ATPase, are not driven by ATP-induced conformational changes.,Haupt M, Bramkamp M, Coles M, Altendorf K, Kessler H J Mol Biol. 2004 Oct 1;342(5):1547-58. PMID:15364580[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Haupt M, Bramkamp M, Heller M, Coles M, Deckers-Hebestreit G, Herkenhoff-Hesselmann B, Altendorf K, Kessler H. The holo-form of the nucleotide binding domain of the KdpFABC complex from Escherichia coli reveals a new binding mode. J Biol Chem. 2006 Apr 7;281(14):9641-9. Epub 2005 Dec 14. PMID:16354672 doi:http://dx.doi.org/10.1074/jbc.M508290200
- ↑ Damnjanovic B, Weber A, Potschies M, Greie JC, Apell HJ. Mechanistic analysis of the pump cycle of the KdpFABC P-type ATPase. Biochemistry. 2013 Aug 20;52(33):5563-76. doi: 10.1021/bi400729e. Epub 2013 Aug, 9. PMID:23930894 doi:http://dx.doi.org/10.1021/bi400729e
- ↑ Siebers A, Altendorf K. The K+-translocating Kdp-ATPase from Escherichia coli. Purification, enzymatic properties and production of complex- and subunit-specific antisera. Eur J Biochem. 1988 Dec 1;178(1):131-40. PMID:2849541
- ↑ Kollmann R, Altendorf K. ATP-driven potassium transport in right-side-out membrane vesicles via the Kdp system of Escherichia coli. Biochim Biophys Acta. 1993 Jun 10;1143(1):62-6. PMID:8499455
- ↑ Haupt M, Bramkamp M, Coles M, Altendorf K, Kessler H. Inter-domain motions of the N-domain of the KdpFABC complex, a P-type ATPase, are not driven by ATP-induced conformational changes. J Mol Biol. 2004 Oct 1;342(5):1547-58. PMID:15364580 doi:http://dx.doi.org/10.1016/j.jmb.2004.07.060
