A capping domain for LRR protein interaction modules

AbstractLeucine-rich repeats (LRR) are protein interaction modules which are present in a large number of proteins with diverse functions. We describe here a novel motif (16–19 residues) downstream of the last, incomplete, LRR in a subfamily of LRR proteins. In the U2A’ spliceosomal protein, this motif is folded into a cap that shields the hydrophobic core of the LRRs from the solvent. Modelling of the LRR-cap in the imidazoline-1 candidate receptor, using the known structure of U2A’ as template, showed a conservation of the basic structural features