2b3r: Difference between revisions

[[Image:2b3r.gif|left|200px]]<br /><applet load="2b3r" size="350" color="white" frame="true" align="right" spinBox="true"  

Phosphatidylinositide (PtdIns) 3-kinase catalyzes the addition of a phosphate group to the 3'-position of phosphatidyl inositol. Accumulated evidence shows that PtdIns 3-kinase can provide a critical signal for cell proliferation, cell survival, membrane trafficking, glucose transport, and membrane ruffling. Mammalian PtdIns 3-kinases are divided into three classes based on structure and substrate specificity. A unique characteristic of class II PtdIns 3-kinases is the presence of both a phox homolog domain and a C2 domain at the C terminus. The biological function of the C2 domain of the class II PtdIns 3-kinases remains to be determined. We have determined the crystal structure of the mCPK-C2 domain, which is the first three-dimensional structural model of a C2 domain of class II PtdIns 3-kinases. Structural studies reveal that the mCPK-C2 domain has a typical anti-parallel beta-sandwich fold. Scrutiny of the surface of this C2 domain has identified three small, shallow sulfate-binding sites. On the basis of the structural features of these sulfate-binding sites, we have studied the lipid binding properties of the mCPK-C2 domain by site-directed mutagenesis. Our results show that this C2 domain binds specifically to PtdIns(3,4)P(2) and PtdIns(4,5)P(2) and that three lysine residues at SBS I site, Lys-1420, Lys-1432, and Lys-1434, are responsible for the phospholipid binding affinity.

2B3R is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Phosphatidylinositol-4-phosphate_3-kinase Phosphatidylinositol-4-phosphate 3-kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.154 2.7.1.154] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2B3R OCA].  

[[Category: Czech, M P.]]

[[Category: Verbasius, J V.]]

[[Category: Zhou, G W.]]

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