1QOI
U4/U6 snRNP-specific cyclophilin SnuCyp-20
Summary for 1QOI
| Entry DOI | 10.2210/pdb1qoi/pdb |
| Descriptor | SNUCYP-20 (2 entities in total) |
| Functional Keywords | isomerase, snucyp-20, cyclophilin, snrnp, spliceosomal |
| Biological source | HOMO SAPIENS (HUMAN) |
| Cellular location | Nucleus speckle : O43447 |
| Total number of polymer chains | 1 |
| Total formula weight | 19230.12 |
| Authors | Reidt, U.,Reuter, K.,Achsel, T.,Ingelfinger, D.,Luehrmann, R.,Ficner, R. (deposition date: 1999-11-09, release date: 2000-04-10, Last modification date: 2023-12-13) |
| Primary citation | Reidt, U.,Reuter, K.,Achsel, T.,Ingelfinger, D.,Luehrmann, R.,Ficner, R. Crystal Structure of the Human U4/U6 Small Nuclear Ribonucleoproteinparticle-Specificsnucyp-20, a Nuclear Cyclophilin J.Biol.Chem., 275:7439-, 2000 Cited by PubMed Abstract: The cyclophilin SnuCyp-20 is a specific component of the human U4/U6 small nuclear ribonucleoprotein particle involved in the nuclear splicing of pre-mRNA. It stably associates with the U4/U6-60kD and -90kD proteins, the human orthologues of the Saccharomyces cerevisiae Prp4 and Prp3 splicing factors. We have determined the crystal structure of SnuCyp-20 at 2.0-A resolution by molecular replacement. The structure of SnuCyp-20 closely resembles that of human cyclophilin A (hCypA). In particular, the catalytic centers of SnuCyp-20 and hCypA superimpose perfectly, which is reflected by the observed peptidyl-prolyl-cis/trans-isomerase activity of SnuCyp-20. The surface properties of both proteins, however, differ significantly. Apart from seven additional amino-terminal residues, the insertion of five amino acids in the loop alpha1-beta3 and of one amino acid in the loop alpha2-beta8 changes the conformations of both loops. The enlarged loop alpha1-beta3 is involved in the formation of a wide cleft with predominantly hydrophobic character. We propose that this enlarged loop is required for the interaction with the U4/U6-60kD protein. PubMed: 10713041DOI: 10.1074/JBC.275.11.7439 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2 Å) |
Structure validation
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