1o7k: Difference between revisions

p47(phox) is a key cytosolic subunit required for activation of phagocyte, NADPH oxidase. The X-ray structure of the p47(phox) PX domain revealed two, distinct basic pockets on the membrane-binding surface, each occupied by a, sulfate. These two pockets have different specificities: one, preferentially binds phosphatidylinositol 3,4-bisphosphate, [PtdIns(3,4)P(2)] and is analogous to the phophatidylinositol 3-phosphate, (PtdIns3P)-binding pocket of p40(phox), while the other binds anionic, phospholipids such as phosphatidic acid (PtdOH) or phosphatidylserine. The, preference of this second site for PtdOH may be related to previously, observed activation of NADPH oxidase by PtdOH. Simultaneous occupancy of, the two phospholipid-binding pockets radically increases membrane, affinity. Strikingly, measurements for full-length p47(phox) show that, membrane interaction by the PX domain is masked by an intramolecular, association with the C-terminal SH3 domain (C-SH3). Either a site-specific, mutation in C-SH3 (W263R) or a mimic of the phosphorylated form of, p47(phox) [Ser(303, 304, 328, 359, 370)Glu] cause a transition from a, closed to an open conformation that binds membranes with a greater, affinity than the isolated PX domain.

1O7K is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Structure known Active Site: API. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1O7K OCA].  

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