title: Intramolecular allosteric interaction in the phospholipase C-δ1 pleckstrin homology domain.
abstract: Protein activities are generally regulated by intramolecular allosteric interactions, by which spatially separated sites in a protein molecule communicate. Intramolecular allosteric interactions in the phospholipase C (PLC)-δ1 pleckstrin homology (PH) domain were investigated by solution NMR spectroscopy for selectively [α-(15)N]Lys-labeled proteins. The results of NMR analyses indicated that the binding of inositol 1,4,5-trisphosphate (IP3) to the protein induces local environmental changes at all lysine residues, including residues such as Lys-43 spatially separated from the specific IP3 binding site consisting of Lys-30, Lys-32, and Lys-57. IP3 binding also induces conformational stabilization of a characteristic short α-helix (α2) from residues 82 to 87. Mutational analyses indicated that an interaction network mainly consisting of the side chains of Lys-30, Lys-32, and Lys-43 exists in the ligand-free protein, and it was therefore predicted that binding of IP3 to the specific site modifies the interaction network, resulting in formation of a new interaction network, in which the side chains of Lys-57 and Phe-87 contribute to stable IP3 binding. These results provide evidence for intramolecular interactions in the PLC-δ1 PH domain, the function of which could be allosterically regulated by modifications at sites spatially separated from the ligand-binding site through the intramolecular interaction network.
authors: Institute for Molecular Science, Okazaki, Japan.
authors: Michikazu
authors: M
authors: Tanio
authors: Katsuyuki
authors: K
authors: Nishimura
mesh_terms: D000495:Allosteric Site; D001798:Blood Proteins / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D008239:Lysine / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D054803:Phospholipase C delta / Q000737:chemistry* / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry* / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D001798:Blood Proteins; D008024:Ligands; D010750:Phosphoproteins; D011994:Recombinant Proteins; C039077:platelet protein P47; D015544:Inositol 1,4,5-Trisphosphate; D054803:Phospholipase C delta; D008239:Lysine