2ag9: Difference between revisions

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-[[Image:2ag9.gif|left|200px]]
+{{Seed}}
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 {{STRUCTURE_2ag9|  PDB=2ag9  |  SCENE=  }}
-'''Crystal Structure of the Y137S mutant of GM2-Activator Protein'''
+===Crystal Structure of the Y137S mutant of GM2-Activator Protein===
-==Overview==
+<!--
-GM2-activator protein (GM2AP) is a lysosomal lipid transfer protein with important biological roles in ganglioside catabolism, phospholipid metabolism, and T-cell activation. Previous studies of crystal structures of GM2AP complexed with the physiological ligand GM2 and platelet activating factor (PAF) have shown binding at two specific locations within the spacious apolar pocket and an ordering effect of endogenous resident lipids. To investigate the structural basis of phospholipid binding further, GM2AP was cocrystallized with phosphatidylcholine (PC), known to interact with GM2AP. Analysis of three crystal forms revealed binding of single chain lipids and fatty acids only and surprisingly not intact PC. The regions of best defined electron density are consistent with the presence of lyso-PC and oleic acid, which constitute deacylation products of PC. Their acyl tails are in stacking contact with shorter, less well-defined stretches of electron density that may represent resident fatty acids. The GM2AP associated hydrolytic activity that generates lyso-PC was further confirmed by mass spectrometry and enzymatic assays. In addition, we report the structures of (i) mutant Y137S, assessing the role of Tyr137 in lipid transfer via the hydrophobic cleft, and (ii) apo-mouse GM2AP, revealing a hydrophobic pocket with a constricted opening. Our structural results provide new insights into the biological functions of GM2AP. The combined effect of hydrolytic and lipid transfer properties has profound implications in cellular signaling.
+The line below this paragraph, {{ABSTRACT_PUBMED_16216074}}, adds the Publication Abstract to the page
+(as it appears on PubMed at http://www.pubmed.gov), where 16216074 is the PubMed ID number.
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+{{ABSTRACT_PUBMED_16216074}}
 ==Disease==
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 ==Reference==
 Crystal structure analysis of phosphatidylcholine-GM2-activator product complexes: evidence for hydrolase activity., Wright CS, Mi LZ, Lee S, Rastinejad F, Biochemistry. 2005 Oct 18;44(41):13510-21. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16216074 16216074]
+Crystal structure of human GM2-activator protein with a novel beta-cup topology., Wright CS, Li SC, Rastinejad F, J Mol Biol. 2000 Dec 1;304(3):411-22. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11090283 11090283]
+Structural analysis of lipid complexes of GM2-activator protein., Wright CS, Zhao Q, Rastinejad F, J Mol Biol. 2003 Aug 22;331(4):951-64. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/12909021 12909021]
 [[Category: Homo sapiens]]
 [[Category: Single protein]]
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 [[Category: Rastinejad, F.]]
 [[Category: Wright, C S.]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 19:00:49 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 23:38:03 2008''