1Y4E

NMR structure of transmembrane segment IV of the NHE1 isoform of the Na+/H+ exchanger


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 1000 
  • Conformers Submitted: 100 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural and functional characterization of transmembrane segment IV of the NHE1 isoform of the Na+/H+ exchanger.

Slepkov, E.R.Rainey, J.K.Li, X.Liu, Y.Cheng, F.J.Lindhout, D.A.Sykes, B.D.Fliegel, L.

(2005) J.Biol.Chem. 280: 17863-17872

  • DOI: 10.1074/jbc.M409608200

  • PubMed Abstract: 
  • The Na(+)/H(+) exchanger isoform 1 is a ubiquitously expressed integral membrane protein that regulates intracellular pH in mammals. We characterized the structural and functional aspects of the critical transmembrane (TM) segment IV. Each residue wa ...

    The Na(+)/H(+) exchanger isoform 1 is a ubiquitously expressed integral membrane protein that regulates intracellular pH in mammals. We characterized the structural and functional aspects of the critical transmembrane (TM) segment IV. Each residue was mutated to cysteine in cysteine-less NHE1. TM IV was exquisitely sensitive to mutation with 10 of 23 mutations causing greatly reduced expression and/or activity. The Phe(161) --> Cys mutant was inhibited by treatment with the water-soluble sulfhydryl-reactive compounds [2-(trimethylammonium)ethyl]methanethiosulfonate and [2-sulfonatoethyl]methanethiosulfonate, suggesting it is a pore-lining residue. The structure of purified TM IV peptide was determined using high resolution NMR in a CD(3)OH:CDCl(3):H(2)O mixture and in Me(2)SO. In CD(3)OH: CDCl(3):H(2)O, TM IV was structured but not as a canonical alpha-helix. Residues Asp(159)-Leu(162) were a series of beta-turns; residues Leu(165)-Pro(168) showed an extended structure, and residues Ile(169)-Phe(176) were helical in character. These three structured regions rotated quite freely with respect to the others. In Me(2)SO, the structure was much less defined. Our results demonstrate that TM IV is an unusually structured transmembrane segment that is exquisitely sensitive to mutagenesis and that Phe(161) is a pore-lining residue.


    Related Citations: 
    • High-yield expression of isotopically labeled peptides for use in NMR studies
      Lindhout, D.A.,Thiessen, A.,Schieve, D.,Sykes, B.D.
      (2003) Protein Sci. 12: 1786


    Organizational Affiliation

    Membrane Protein Research Group, Department of Biochemistry, Canadian Institutes of Health Research Group in Protein Structure and Function, and Protein Engineering Network of Centers of Excellence, University of Alberta, Edmonton, Alberta, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Sodium/hydrogen exchanger 1
A
27Homo sapiensMutation(s): 0 
Gene Names: SLC9A1 (APNH1, NHE1)
Find proteins for P19634 (Homo sapiens)
Go to Gene View: SLC9A1
Go to UniProtKB:  P19634
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
HSL
Query on HSL
A
L-PEPTIDE LINKINGC4 H7 N O2SER
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 1000 
  • Conformers Submitted: 100 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 1Y4E Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-02-01
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance