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PDBsum entry 2e30
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Metal binding protein/transport protein
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PDB id
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2e30
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References listed in PDB file
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Key reference
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Title
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Solution structure of the cytoplasmic region of na+/h+ exchanger 1 complexed with essential cofactor calcineurin b homologous protein 1.
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Authors
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M.Mishima,
S.Wakabayashi,
C.Kojima.
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Ref.
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J Biol Chem, 2007,
282,
2741-2751.
[DOI no: ]
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PubMed id
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Note In the PDB file this reference is
annotated as "TO BE PUBLISHED".
The citation details given above were identified by an automated
search of PubMed on title and author
names, giving a
perfect match.
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Abstract
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Na+/H+ exchanger 1 (NHE1) regulates intracellular pH, Na+ content, and cell
volume. Calcineurin B homologous protein 1 (CHP1) serves as an essential
cofactor that facilitates NHE1 exchange activity under physiological conditions
by direct binding to the cytoplasmic juxtamembrane region of NHE1. Here we
describe the solution structure of the cytoplasmic juxtamembrane region of NHE1
complexed with CHP1. The region of NHE1 forms an amphipathic helix, which is
induced by CHP1 binding, and CHP1 possesses a large hydrophobic cleft formed by
EF-hand helices. The apolar side of the NHE1 helix participates in extensive
hydrophobic interactions with the cleft of CHP1. We suggest that helix formation
of the cytoplasmic region of NHE1 by CHP1 is a prerequisite for generating the
active form of NHE1. The molecular recognition detailed in this study also
provides novel insight into the target binding mechanism of EF-hand proteins.
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Figure 3.
FIGURE 3. Solution structure of the NHE1-CHP1 complex. A,
stereoview of the backbone superpositions of the final 20
simulated annealing structures of the NHE1-CHP1 complex. B,
ribbon drawing of the representative NHE1-CHP1 structure
complex. A and B, residues 517–538 of NHE1 and 10–192 of
CHP1 are shown. The N- and C-terminal domains of CHP1 are
colored in blue and magenta, respectively, and the CHP loop is
colored in gray. NHE1 is shown in green.Ca^2+ ions are shown by
gold spheres.
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Figure 4.
FIGURE 4. Molecular surface of the NHE1-CHP1 complex. A,
molecular surface of CHP1 and backbone tube representation of
NHE1 with yellow stick that shows the hydrophobic side chains.
The N- and C-terminal domains of CHP1 are colored in blue and
magenta, respectively. B, molecular surface of NHE1 and backbone
tube representation of CHP1. Hydrophobic, acidic, and polar
residues are colored in yellow, red, and blue, respectively.
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The above figures are
reprinted
by permission from the ASBMB:
J Biol Chem
(2007,
282,
2741-2751)
copyright 2007.
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