1dro
NMR STRUCTURE OF THE CYTOSKELETON/SIGNAL TRANSDUCTION PROTEIN
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OverviewOverview
BACKGROUND: The pleckstrin homology (PH) domain, which is approximately, 100 amino acids long, has been found in about 70 proteins involved in, signal transduction and cytoskeletal function, a frequency comparable to, SH2 (src homology 2) and SH3 domains. PH domains have been shown to bind, the beta gamma-subunits of G-proteins and phosphatidylinositol, 4,5-bisphosphate (PIP2). It is conceivable that the PH domain of, beta-spectrin plays a part in the association of spectrin with the plasma, membrane of cells. RESULTS: We have solved the solution structure of the, 122-residue PH domain of Drosophila beta-spectrin. The overall fold, consists of two antiparallel beta-sheets packing against each other at an, angle of approximately 60 degrees to form a beta-sandwich, a two-turn, alpha-helix unique to spectrin PH domains, and a four-turn C-terminal, alpha-helix. One of the major insertions in beta-spectrin PH domains forms, a long, basic surface loop and appears to undergo slow conformational, exchange in solution. This loop shows big spectral changes upon addition, of D-myo-inositol 1,4,5-trisphosphate (IP3). CONCLUSIONS: We propose that, the groove at the outer surface of the second beta-sheet is an important, site of association with other proteins. This site and the possible, lipid-binding site can serve to localize the spectrin network under the, plasma membrane. More generally, it has to be considered that the common, fold observed for the PH domain structures solved so far does not, necessarily mean that all PH domains have similar functions. In fact, the, residues constituting potential binding sites for ligands or other, proteins are only slightly conserved between different PH domains.
About this StructureAbout this Structure
1DRO is a Single protein structure of sequence from Drosophila melanogaster. Full crystallographic information is available from OCA.
ReferenceReference
Solution structure of the pleckstrin homology domain of Drosophila beta-spectrin., Zhang P, Talluri S, Deng H, Branton D, Wagner G, Structure. 1995 Nov 15;3(11):1185-95. PMID:8591029
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