Abstract Summary: PRIDE-NMR is a fast novel method to relate known protein folds to NMR distance restraints. It can be used to obtain a first guess about a structure being determined, as well as to estimate the completeness or verify the correctness of NOE data. Availability: The PRIDE-NMR server is available at http://www.icgeb.org/pride Contact: [email protected] Supplementary information: Description of the server and details of the tests presented can be found at http://www.icgeb.org/pride

Members of the pacifastin family are small, approximately 35-residue serine protease inhibitors isolated from arthropod species. Several locust inhibitors exhibit intriguing taxon specificity while others do not. The structural basis of this phenomenon may lie in the different dynamical properties of the proteins originating from different stabilizing interactions. In this study, we identify new members of the family to confirm the universal role of these interactions in the family. Structural investigations show that both the disulfide pattern and the stabilizing interactions are unique among small all-beta proteins.