Crotin Ⅱ is one of the ribosome inactivating proteins (RIPs). It belongs to RNA hydrolase. The crystals of crotin Ⅱ are hexagonal with a=b= 94. 62, c=28. 44 A, space group P61, Mr= 14900 Da. The structure was solved...Crotin Ⅱ is one of the ribosome inactivating proteins (RIPs). It belongs to RNA hydrolase. The crystals of crotin Ⅱ are hexagonal with a=b= 94. 62, c=28. 44 A, space group P61, Mr= 14900 Da. The structure was solved by molecularreplacement methed using the molecular structure of RNase T1 as a search model andrefined to R= 0. 25 for the reflections within 10- 2. 5 A resolution range. The refinedmodel cotains one α-helix, one two-strand antiparallel β-sheet and one five-strand an-tiparallel β-sheet. Four conservative residues His47, Glu77, Arg102 and His117 gathering in the cleft of the structure form the possible active site of crotin Ⅱ.展开更多
Basic phospholipase A2 (BPLA2) from the venom of Agkistrodon halys pallas has a strong ability to hemolyze erythrocytes. The asymmetrical unit of P212121 crystal of BPLA2 contains two molecules. Self-rotation function...Basic phospholipase A2 (BPLA2) from the venom of Agkistrodon halys pallas has a strong ability to hemolyze erythrocytes. The asymmetrical unit of P212121 crystal of BPLA2 contains two molecules. Self-rotation function was used to study the orientation relationship of these two molecules. Cross-rotation and translation functions were then used to determine the orientations and positions of the two molecules in the unit cell. The model building and preliminary structure refinement were carried out. The result shows that the two molecules in the asymmetrical unit of orthorhombic crystal are related by a non-crystallographic 2-fold symmetry axis.展开更多
文摘Crotin Ⅱ is one of the ribosome inactivating proteins (RIPs). It belongs to RNA hydrolase. The crystals of crotin Ⅱ are hexagonal with a=b= 94. 62, c=28. 44 A, space group P61, Mr= 14900 Da. The structure was solved by molecularreplacement methed using the molecular structure of RNase T1 as a search model andrefined to R= 0. 25 for the reflections within 10- 2. 5 A resolution range. The refinedmodel cotains one α-helix, one two-strand antiparallel β-sheet and one five-strand an-tiparallel β-sheet. Four conservative residues His47, Glu77, Arg102 and His117 gathering in the cleft of the structure form the possible active site of crotin Ⅱ.
基金Project supported by Chinese Academy of Sciences.
文摘Basic phospholipase A2 (BPLA2) from the venom of Agkistrodon halys pallas has a strong ability to hemolyze erythrocytes. The asymmetrical unit of P212121 crystal of BPLA2 contains two molecules. Self-rotation function was used to study the orientation relationship of these two molecules. Cross-rotation and translation functions were then used to determine the orientations and positions of the two molecules in the unit cell. The model building and preliminary structure refinement were carried out. The result shows that the two molecules in the asymmetrical unit of orthorhombic crystal are related by a non-crystallographic 2-fold symmetry axis.
