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PDBsum entry 1omr
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Metal binding protein
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PDB id
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1omr
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Impact of n-Terminal myristoylation on the ca2+-Dependent conformational transition in recoverin.
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Authors
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O.H.Weiergräber,
I.I.Senin,
P.P.Philippov,
J.Granzin,
K.W.Koch.
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Ref.
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J Biol Chem, 2003,
278,
22972-22979.
[DOI no: ]
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PubMed id
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Abstract
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Recoverin is a Ca2+-regulated signal transduction modulator found in vertebrate
retina that has been shown to undergo dramatic conformational changes upon Ca2+
binding to its two functional EF-hand motifs. To elucidate the differential
impact of the N-terminal myristoylation as well as occupation of the two Ca2+
binding sites on recoverin structure and function, we have investigated a
non-myristoylated E85Q mutant exhibiting virtually no Ca2+ binding to EF-2.
Crystal structures of the mutant protein as well as the non-myristoylated
wild-type have been determined. Although the non-myristoylated E85Q mutant does
not display any functional activity, its three-dimensional structure in the
presence of Ca2+ resembles the myristoylated wild-type with two Ca2+ but is
quite dissimilar from the myristoylated E85Q mutant. We conclude that the
N-terminal myristoyl modification significantly stabilizes the conformation of
the Ca2+-free protein (i.e. the T conformation) during the stepwise transition
toward the fully Ca2+-occupied state. On the basis of these observations, a
refined model for the role of the myristoyl group as an intrinsic allosteric
modulator is proposed.
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Figure 7.
FIG. 7. Arrangement of side chains critical for interaction
with rhodopsin kinase (as defined in Ref. 41). Residues probably
involved in the binding interface according to these authors are
colored in red, those of minor significance in orange.
Abbreviations are as in Fig. 6.
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Figure 8.
FIG. 8. C[  ]trace superposition
(identical to Fig. 5 with  180° rotation) of
non-myristoylated recoverin with one Ca^2+ (darker colors) and
myristoylated recoverin with two Ca^2+ (lighter colors) showing
positional re-arrangement of hydrophobic residues forming the
patch defined in Fig. 6 (yellow backbone) and of side chains
probably (light and dark red) and possibly (light and dark
orange) involved in rhodopsin kinase inhibition (see Fig. 7).
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The above figures are
reprinted
by permission from the ASBMB:
J Biol Chem
(2003,
278,
22972-22979)
copyright 2003.
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