From Proteopediaproteopedia link
Crystal structure of human cyclophilin D at 1.54 A resolution at room temperature
[PPIF_HUMAN] PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. Involved in regulation of the mitochondrial permeability transition pore (mPTP). It is proposed that its association with the mPTP is masking a binding site for inhibiting inorganic phosphate (Pi) and promotes the open probablity of the mPTP leading to apoptosis or necrosis; the requirement of the PPIase activity for this function is debated. In cooperation with mitochondrial TP53 is involved in activating oxidative stress-induced necrosis. Involved in modulation of mitochondrial membrane F(1)F(0) ATP synthase activity and regulation of mitochondrial matrix adenine nucleotide levels. Has anti-apoptotic activity independently of mPTP and in cooperation with BCL2 inhibits cytochrome c-dependent apoptosis. 
Publication Abstract from PubMed
X-ray crystallography is now a recognized technique for ligand screening, especially for fragment-based drug design. However, protein crystal handling is still tedious and limits further automation. An alternative method for the solution of crystal structures of proteins in complex with small ligands is proposed. Crystallization drops are directly exposed to an X-ray beam after cocrystallization or soaking with the desired ligands. The use of dedicated plates in connection with an optimal parametrization of the G-rob robot allows efficient data collection. Three proteins currently under study in our laboratory for ligand screening by X-ray crystallography were used as validation test cases. The protein crystals belonged to different space groups, including a challenging monoclinic case. The resulting diffraction data can lead to clear ligand recognition, including indication of alternating conformations. These results demonstrate a possible method for automation of ligand screening by X-ray crystallography.
In-plate protein crystallization, in situ ligand soaking and X-ray diffraction.,le Maire A, Gelin M, Pochet S, Hoh F, Pirocchi M, Guichou JF, Ferrer JL, Labesse G Acta Crystallogr D Biol Crystallogr. 2011 Sep;67(Pt 9):747-55. doi:, 10.1107/S0907444911023249. Epub 2011 Aug 9. PMID:21904027
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.