1gh4

Structure of the triple mutant (K56M, K120M, K121M) of phospholipase A2

spinqualitylabelsall models 1gh4, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1gh4 is a 1 chain structure with sequence from Bos taurus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.9Å Ligands: CA, MPD Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function PA21B_BOVIN PA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Phospholipase A(2) catalyses hydrolysis of the ester bond at the C2 position of 3-sn-phosphoglycerides. Here we report the 1.9A resolution crystal structure of the triple mutant K56,120,121M of bovine pancreatic phospholipase A(2). The structure was solved by molecular replacement method using the orthorhombic form of the recombinant phospholipase A(2). The final protein model contains all the 123 amino acid residues, two calcium ions, 125 water molecules and one 2-methyl-2-4-pentanediol molecule. The model has been refined to a crystallographic R-factor of 19.6% (R(free) of 25.9%) for all data between 14.2A and 1.9A. The residues 62-66, which are in a surface loop, are always disordered in the structures of bovine pancreatic phospholipase A(2) and its mutants. It is interesting to note that the residues 62-66 in the present structure is ordered and the conformation varies substantially from those in the previously published structures of this enzyme. An unexpected and interesting observation in the present structure is that, in addition to the functionally important calcium ion in the active site, one more calcium ion is found near the N terminus. Detailed structural analyses suggest that binding of the second calcium ion could be responsible for the conformational change and the ordering of the surface loop. Furthermore, the results suggest a structural reciprocity between the k(cat)(*) allosteric site and surface loop at the i-face, which represents a newly identified structural property of secreted phospholipase A(2). Observation of additional calcium ion in the crystal structure of the triple mutant K56,120,121M of bovine pancreatic phospholipase A2.,Rajakannan V, Yogavel M, Poi MJ, Jeyaprakash AA, Jeyakanthan J, Velmurugan D, Tsai MD, Sekar K J Mol Biol. 2002 Dec 6;324(4):755-62. PMID:12460575 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Phospholipase A2 3D structures

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