This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1mzw
From Proteopedia
|
Crystal structure of a U4/U6 snRNP complex between human spliceosomal cyclophilin H and a U4/U6-60K peptide
Contents |
Overview
The spliceosomal cyclophilin H is a specific component of the human U4/U6 small nuclear ribonucleoprotein particle, interacting with homologous sequences in the proteins U4/U6-60K and hPrp18 during pre-mRNA splicing. We determined the crystal structure of the complex comprising cyclophilin H and the cognate domain of U4/U6-60K. The 31 amino acid fragment of U4/U6-60K is bound to a region remote from the cyclophilin active site. Residues Ile118-Phe121 of U4/U6-60K expand the central beta-sheet of cyclophilin H and the side-chain of Phe121 inserts into a hydrophobic cavity. Concomitantly, in the crystal the cyclophilin H active site is occupied by the N terminus of a neighboring cyclophilin H molecule in a substrate-like manner, indicating the capacity of joint binding to a substrate and to U4/U6-60K. Free and complexed cyclophilin H have virtually identical conformations suggesting that the U4/U6-60K binding site is pre-shaped and the peptidyl-prolyl-cis/trans isomerase activity is unaffected by complex formation. The complex defines a novel protein-protein interaction mode for a cyclophilin, allowing cyclophilin H to mediate interactions between different proteins inside the spliceosome or to initiate from its binding platforms isomerization or chaperoning activities.
Disease
Known diseases associated with this structure: Cardiomyopathy, dilated OMIM:[605906], Cardiomyopathy, dilated, with left ventricular noncompaction OMIM:[605906], Myopathy, myofibrillar, ZASP-related OMIM:[605906]
About this Structure
1MZW is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystal structure of a complex between human spliceosomal cyclophilin H and a U4/U6 snRNP-60K peptide., Reidt U, Wahl MC, Fasshauer D, Horowitz DS, Luhrmann R, Ficner R, J Mol Biol. 2003 Aug 1;331(1):45-56. PMID:12875835
Page seeded by OCA on Thu Feb 21 14:00:47 2008
