2KBV

Structural and functional analysis of TM XI of the NHE1 isoform of thE NA+/H+ exchanger


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 40 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural and Functional Analysis of Transmembrane XI of the NHE1 Isoform of the Na+/H+ Exchanger

Lee, B.L.Li, X.Liu, Y.Sykes, B.D.Fliegel, L.

(2009) J.Biol.Chem. 284: 11546-11556

  • DOI: 10.1074/jbc.M809201200

  • PubMed Abstract: 
  • The Na(+)/H(+) exchanger isoform 1 is a ubiquitously expressed integral membrane protein that regulates intracellular pH in mammals by extruding an intracellular H(+) in exchange for one extracellular Na(+). We characterized structural and functional ...

    The Na(+)/H(+) exchanger isoform 1 is a ubiquitously expressed integral membrane protein that regulates intracellular pH in mammals by extruding an intracellular H(+) in exchange for one extracellular Na(+). We characterized structural and functional aspects of the critical transmembrane (TM) segment XI (residues 449-470) by using cysteine scanning mutagenesis and high resolution NMR. Each residue of TM XI was mutated to cysteine in the background of the cysteine-less protein and the sensitivity to water-soluble sulfhydryl reactive compounds MTSET ((2-(trimethylammonium) ethyl)methanethiosulfonate) and MTSES ((2-sulfonatoethyl) methanethiosulfonate) was determined for those residues with at least moderate activity remaining. Of the residues tested, only proteins with mutations L457C, I461C, and L465C were inhibited by MTSET. The activity of the L465C mutant was almost completely eliminated, whereas that of the L457C and I461C mutants was partially affected. The structure of a peptide representing TM XI (residues Lys(447)-Lys(472)) was determined using high resolution NMR spectroscopy in dodecylphosphocholine micelles. The structure consisted of helical regions between Asp(447)-Tyr(454) and Phe(460)-Lys(471) at the N and C termini of the peptide, respectively, connected by a region with poorly defined, irregular structure consisting of residues Gly(455)-Gly(459). TM XI of NHE1 had a structural similarity to TM XI of the Escherichia coli Na(+)/H(+) exchanger NhaA. The results suggest that TM XI is a discontinuous helix, with residue Leu(465) contributing to the pore.


    Organizational Affiliation

    Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Sodium/hydrogen exchanger 1
A
28Homo sapiensGene Names: SLC9A1 (APNH1, NHE1)
Find proteins for P19634 (Homo sapiens)
Go to Gene View: SLC9A1
Go to UniProtKB:  P19634
Small Molecules
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
NH2
Query on NH2
A
NON-POLYMERH2 N

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ACE
Query on ACE
A
NON-POLYMERC2 H4 O

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Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 40 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 2KBV Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-01-27
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance