Structural and functional analysis of tm vi 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 

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Structural and Functional Analysis of Transmembrane Segment VI of the NHE1 Isoform of the Na+/H+ Exchanger.

Tzeng, J.Lee, B.L.Sykes, B.D.Fliegel, L.

(2010) J Biol Chem 285: 36656-36665

  • DOI: https://doi.org/10.1074/jbc.M110.161471
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The Na(+)/H(+) exchanger isoform 1 is a ubiquitously expressed integral membrane protein. It resides on the plasma membrane of cells and regulates intracellular pH in mammals by extruding an intracellular H(+) in exchange for one extracellular Na(+). We characterized structural and functional aspects of the transmembrane segment (TM) VI (residues 227-249) by using cysteine scanning mutagenesis and high resolution NMR. Each residue of TM VI was mutated to cysteine in the background of the cysteineless NHE1 protein, and the sensitivity to water-soluble sulfhydryl-reactive compounds (2-(trimethylammonium)ethyl)methanethiosulfonate (MTSET) and (2-sulfonatoethyl)methanethiosulfonate (MTSES) was determined for those residues with significant activity remaining. Three residues were essentially inactive when mutated to Cys: Asp(238), Pro(239), and Glu(247). Of the remaining residues, proteins with the mutations N227C, I233C, and L243C were strongly inhibited by MTSET, whereas amino acids Phe(230), Gly(231), Ala(236), Val(237), Ala(244), Val(245), and Glu(248) were partially inhibited by MTSET. MTSES did not affect the activity of the mutant NHE1 proteins. The structure of a peptide representing TM VI was determined using high resolution NMR spectroscopy in dodecylphosphocholine micelles. TM VI contains two helical regions oriented at an approximate right angle to each other (residues 229-236 and 239-250) surrounding a central unwound region. This structure bears a resemblance to TM IV of the Escherichia coli protein NhaA. The results demonstrate that TM VI of NHE1 is a discontinuous pore-lining helix with residues Asn(227), Ile(233), and Leu(243) lining the translocation pore.

  • Organizational Affiliation

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

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Sodium/hydrogen exchanger 133Homo sapiensMutation(s): 2 
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for P19634 (Homo sapiens)
Explore P19634 
Go to UniProtKB:  P19634
GTEx:  ENSG00000090020 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP19634
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

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

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-09-15
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2020-02-05
    Changes: Data collection, Database references, Other
  • Version 1.3: 2024-05-01
    Changes: Data collection, Database references