protein structure communications
The crystal structure of cyclophilin from Leishmania donovani (LdCyp) has been determined and refined at 1.97 Å resolution to a crystallographic R factor of 0.178 (Rfree = 0.197). The structure was solved by molecular replacement using cyclophilin from Trypanosoma cruzi as the search model. LdCyp exhibits complete structural conservation of the cyclosporin-binding site with respect to the homologous human protein, as anticipated from LdCyp–cyclosporin binding studies. Comparisons with other cyclophilins show deviations primarily in the loop regions. The solvent structure encompassing the molecule has also been analyzed in some detail.