Crystal structure of arabidopsis thaliana cyclophilin 38 (ATCYP38)
[CYP38_ARATH] PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. Required for the assembly and stabilization of PSII.
Publication Abstract from PubMed
Cyclophilin38 (CYP38) is one of the highly divergent cyclophilins from Arabidopsis thaliana. Here, we report the crystal structure of the At-CYP38 protein (residues 83 to 437 of 437 amino acids) at 2.39-A resolution. The structure reveals two distinct domains: an N-terminal helical bundle and a C-terminal cyclophilin beta-barrel, connected by an acidic loop. Two N-terminal beta-strands become part of the C-terminal cyclophilin beta-barrel, thereby making a previously undiscovered domain organization. This study shows that CYP38 does not possess peptidyl-prolyl cis/trans isomerase activity and identifies a possible interaction of CYP38 with the E-loop of chlorophyll protein47 (CP47), a component of photosystem II. The interaction of CYP38 with the E-loop of CP47 is mediated through its cyclophilin domain. The N-terminal helical domain is closely packed together with the putative C-terminal cyclophilin domain and establishes a strong intramolecular interaction, thereby preventing the access of the cyclophilin domain to other proteins. This was further verified by protein-protein interaction assays using the yeast two-hybrid system. Furthermore, the non-Leucine zipper N-terminal helical bundle contains several new elements for protein-protein interaction that may be of functional significance. Together, this study provides the structure of a plant cyclophilin and explains a possible mechanism for autoinhibition of its function through an intramolecular interaction.
Crystal structure of Arabidopsis cyclophilin38 reveals a previously uncharacterized immunophilin fold and a possible autoinhibitory mechanism.,Vasudevan D, Fu A, Luan S, Swaminathan K Plant Cell. 2012 Jun;24(6):2666-74. doi: 10.1105/tpc.111.093781. Epub 2012 Jun, 15. PMID:22706283
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.