1h0p | pdb_00001h0p
Cyclophilin_5 from C. elegans
Structural highlights
FunctionCYP5_CAEEL PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. 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 PubMedThe free-living nematode Caenorhabditis elegans expresses 18 cyclophilin isoforms, eight of which are conserved single domain forms, comprising two closely related secreted or type B forms (CYP-5 and CYP-6). Recombinant CYP-5 has been purified, crystallised and the X-ray structure solved to a resolution of 1.75A. The detailed molecular architecture most strongly resembles the structure of human cyclophilin B with conserved changes in loop structure and N and C-terminal extensions. Interestingly, the active site pocket is occupied by a molecule of dithiothreitol though this has little effect on the geometry of the active site which is similar to other cyclophilin structures. The peptidyl-prolyl isomerase activity of CYP-5 has been characterised against the substrate N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, and gives a k(cat)/K(m) value of 3.6x10(6)M(-1)s(-1) that compares with a value of 6.3x10(6)M(-1)s(-1) for human cyclophilin B. The immunosuppressive drug cyclosporin A binds and inhibits CYP-5 with an IC(50) value of 50nM, which is comparable to the value of 84nM found for human cyclophilin B. CYP-6 has 67% sequence identity with CYP-5 and a molecular model was built based on the CYP-5 crystal structure. The model shows that CYP-5 and CYP-6 are likely to have very similar structures, but with a markedly increased number of negative charges distributed around the surface of CYP-6. The spatial expression patterns of the cyclophilin B isoforms were examined using transgenic animals carrying a LacZ reporter fusion to these genes, and both cyp-5 and cyp-6 are found to be expressed in an overlapping fashion in the nematode gut. The temporal expression pattern of cyp-5 was further determined and revealed a constitutive expression pattern, with highest abundance levels being found in the embryo. Structural and biological characterisation of the gut-associated cyclophilin B isoforms from Caenorhabditis elegans.,Picken NC, Eschenlauer S, Taylor P, Page AP, Walkinshaw MD J Mol Biol. 2002 Sep 6;322(1):15-25. PMID:12215411[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences | ||||||||||||||||||||
