Structural highlights
Function
[PPIH_HUMAN] PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. Participates in pre-mRNA splicing. May play a role in the assembly of the U4/U5/U6 tri-snRNP complex. May act as a chaperone.[1] [2] [3] [PRP4_HUMAN] Involved in pre-mRNA splicing.
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
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.
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[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Teigelkamp S, Achsel T, Mundt C, Gothel SF, Cronshagen U, Lane WS, Marahiel M, Luhrmann R. The 20kD protein of human [U4/U6.U5] tri-snRNPs is a novel cyclophilin that forms a complex with the U4/U6-specific 60kD and 90kD proteins. RNA. 1998 Feb;4(2):127-41. PMID:9570313
- ↑ Horowitz DS, Lee EJ, Mabon SA, Misteli T. A cyclophilin functions in pre-mRNA splicing. EMBO J. 2002 Feb 1;21(3):470-80. PMID:11823439
- ↑ Reidt U, Wahl MC, Fasshauer D, Horowitz DS, Luhrmann R, Ficner R. Crystal structure of a complex between human spliceosomal cyclophilin H and a U4/U6 snRNP-60K peptide. J Mol Biol. 2003 Aug 1;331(1):45-56. PMID:12875835
- ↑ Reidt U, Wahl MC, Fasshauer D, Horowitz DS, Luhrmann R, Ficner R. Crystal structure of a complex between human spliceosomal cyclophilin H and a U4/U6 snRNP-60K peptide. J Mol Biol. 2003 Aug 1;331(1):45-56. PMID:12875835
