2HTG

Structural and functional characterization of TM VII of the NHE1 isoform of the Na+/H+ exchanger


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 120 
  • Conformers Submitted: 66 
  • 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 VII of the Na(+)/H(+) exchanger isoform 1

Ding, J.Rainey, J.K.Xu, C.Sykes, B.D.Fliegel, L.

(2006) J.Biol.Chem. 281: 29817-29829

  • DOI: 10.1074/jbc.M606152200

  • PubMed Abstract: 
  • The Na(+)/H(+) exchanger isoform 1 is an integral membrane protein that regulates intracellular pH by exchanging one intracellular H(+) for one extracellular Na(+). It is composed of an N-terminal membrane domain of 12 transmembrane segments and an i ...

    The Na(+)/H(+) exchanger isoform 1 is an integral membrane protein that regulates intracellular pH by exchanging one intracellular H(+) for one extracellular Na(+). It is composed of an N-terminal membrane domain of 12 transmembrane segments and an intracellular C-terminal regulatory domain. We characterized the structural and functional aspects of the critical transmembrane segment VII (TM VII, residues 251-273) by using alanine scanning mutagenesis and high resolution NMR. Each residue of TM VII was mutated to alanine, the full-length protein expressed, and its activity characterized. TM VII was sensitive to mutation. Mutations at 13 of 22 residues resulted in severely reduced activity, whereas other mutants exhibited varying degrees of decreases in activity. The impaired activities sometimes resulted from low expression and/or low surface targeting. Three of the alanine scanning mutant proteins displayed increased, and two displayed decreased resistance to the Na(+)/H(+) exchanger isoform 1 inhibitor EMD87580. The structure of a peptide of TM VII was determined by using high resolution NMR in dodecylphosphocholine micelles. TM VII is predominantly alpha-helical, with a break in the helix at the functionally critical residues Gly(261)-Glu(262). The relative positions and orientations of the N- and C-terminal helical segments are seen to vary about this extended segment in the ensemble of NMR structures. Our results show that TM VII is a critical transmembrane segment structured as an interrupted helix, with several residues that are essential to both protein function and sensitivity to inhibition.


    Organizational Affiliation

    Department of Biochemistry and Protein Engineering Network of Centres of Excellence, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
NHE1 isoform of Na+/H+ exchanger 1
A
28Meriones unguiculatusMutation(s): 0 
Find proteins for O08938 (Meriones unguiculatus)
Go to UniProtKB:  O08938
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
NH2
Query on NH2
A
NON-POLYMERH2 N

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Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 120 
  • Conformers Submitted: 66 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 2HTG Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-08-08
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance