1ht9
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DOMAIN SWAPPING EF-HANDS
OverviewOverview
The structure of calbindin D(9k) with two substitutions was determined by, X-ray crystallography at 1.8-A resolution. Unlike wild-type calbindin, D(9k), which is a monomeric protein with two EF-hands, the structure of, the mutated calbindin D(9k) reveals an intertwined dimer. In the dimer, two EF-hands of the monomers have exchanged places, and thus a 3D, domain-swapped dimer has been formed. EF-hand I of molecule A is packed, toward EF-hand II of molecule B and vice versa. The formation of a, hydrophobic cluster, in a region linking the EF-hands, promotes the, conversion of monomers to 3D domain-swapped dimers. We propose a mechanism, by which domain swapping takes place via the apo form of calbindin D(9k)., Once formed, the calbindin D(9k) dimers are remarkably stable, as with, even larger misfolded aggregates like amyloids. Thus calbindin D(9k), dimers cannot be converted to monomers by dilution. However, heating can, be used for conversion, indicating high energy barriers separating, monomers from dimers.
About this StructureAbout this Structure
1HT9 is a Single protein structure of sequence from Bos taurus with CA as ligand. Full crystallographic information is available from OCA.
ReferenceReference
An extended hydrophobic core induces EF-hand swapping., Hakansson M, Svensson A, Fast J, Linse S, Protein Sci. 2001 May;10(5):927-33. PMID:11316872
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