1a3d: Difference between revisions
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==Overview== | ==Overview== | ||
Three crystal forms of Naja naja naja phospholipase A2 were discovered, through random crystallization screening, including two heretofore, uncharacterized forms. The crystallization conditions for both of these, novel crystal forms are Ca(2+)-free whereas previously reported conditions, include Ca2+. One of the new crystal forms has a cubic lattice in the, space group P2(1)3 (a = b = c = 69.24 A), the other has an orthorhombic, lattice in the space group P2(1)2(1)2(1) (a = 67.22 A, b = 73.48 A, c =, 87.52 A) and a previously characterized crystal belong to the tetragonal, space group P4(3)2(1)2 (a = b = 88.6 A, c = 107.4 A). The structure from, the cubic crystal form has been determined to 1.8 A and refined to an, R-factor of 17% while the structure from the orthorhombic form has been, ... | Three crystal forms of Naja naja naja phospholipase A2 were discovered, through random crystallization screening, including two heretofore, uncharacterized forms. The crystallization conditions for both of these, novel crystal forms are Ca(2+)-free whereas previously reported conditions, include Ca2+. One of the new crystal forms has a cubic lattice in the, space group P2(1)3 (a = b = c = 69.24 A), the other has an orthorhombic, lattice in the space group P2(1)2(1)2(1) (a = 67.22 A, b = 73.48 A, c =, 87.52 A) and a previously characterized crystal belong to the tetragonal, space group P4(3)2(1)2 (a = b = 88.6 A, c = 107.4 A). The structure from, the cubic crystal form has been determined to 1.8 A and refined to an, R-factor of 17% while the structure from the orthorhombic form has been, determined to 2.65 A and has been refined to an R-factor of 21%. The, determination of the cubic structure extends the resolution to which, structures of this molecule have been determined from 2.3 A to 1.8 A. The, two newly determined structures, in combination with the previously, determined structure, generate an informative structural ensemble from, which structural changes due to Ca2+, which is required for catalysis, and, the effect of crystal contacts on side-chain conformations and oligomeric, association can be inferred. Both of the newly determined structures, reveal a trimeric oligomer as observed in the tetragonal structure; this, appears to be a unique feature of the Naja naja naja enzyme. | ||
==About this Structure== | ==About this Structure== | ||
1A3D is a | 1A3D is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Naja_naja Naja naja] with NA as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Phospholipase_A(2) Phospholipase A(2)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.4 3.1.1.4] Structure known Active Site: CAB. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1A3D OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: trimer]] | [[Category: trimer]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 15:18:47 2007'' | ||
