1mrj

STUDIES ON CRYSTAL STRUCTURES ACTIVE CENTER GEOMETRY AND DEPURINE MECHANISM OF TWO RIBOSOME-INACTIVATING PROTEINSSTUDIES ON CRYSTAL STRUCTURES ACTIVE CENTER GEOMETRY AND DEPURINE MECHANISM OF TWO RIBOSOME-INACTIVATING PROTEINS

Structural highlights 1mrj is a 1 chain structure with sequence from Chinese cucumber. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [RIPT_TRIKI] Inactivates eukaryotic 60S ribosomal subunits. 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 Two ribosome-inactivating proteins, trichosanthin and alpha-momorcharin, have been studied in the forms of complexes with ATP or formycin, by an X-ray-crystallographic method at 1.6-2.0 A (0.16-0.20 nm) resolution. The native alpha-momorcharin had been studied at 2.2 A resolution. Structures of trichosanthin were determined by a multiple isomorphous replacement method. Structures of alpha-momorcharin were determined by a molecular replacement method using refined trichosanthin as the searching model. Small ligands in all these complexes have been recognized and built on the difference in electron density. All these structures have been refined to achieve good results, both in terms of crystallography and of ideal geometry. These two proteins show considerable similarity in their three-dimensional folding and to that of related proteins. On the basis of these structures, detailed geometries of the active centres of these two proteins are described and are compared with those of related proteins. In all complexes the interactions between ligand atoms and protein atoms, including hydrophobic forces, aromatic stacking interactions and hydrogen bonds, are found to be specific towards the adenine base. The relationship between the sequence conservation of ribosome-inactivating proteins and their active-centre geometry was analysed. A depurinating mechanism of ribosome-inactivating proteins is proposed on the basis of these results. The N-7 atom of the substrate base group is proposed to be protonated by an acidic residue in the active centre. Studies on crystal structures, active-centre geometry and depurinating mechanism of two ribosome-inactivating proteins.,Huang Q, Liu S, Tang Y, Jin S, Wang Y Biochem J. 1995 Jul 1;309 ( Pt 1):285-98. PMID:7619070 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 1mrj, resolution 1.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image