title: A structural basis of the interactions between leucine-rich repeats and protein ligands.
abstract: The leucine-rich repeat is a recently characterized structural motif used in molecular recognition processes as diverse as signal transduction, cell adhesion, cell development, DNA repair and RNA processing. We present here the crystal structure at 2.5 A resolution of the complex between ribonuclease A and ribonuclease inhibitor, a protein built entirely of leucine-rich repeats. The unusual non-globular structure of ribonuclease inhibitor, its solvent-exposed parallel beta-sheet and the conformational flexibility of the structure are used in the interaction; they appear to be the principal reasons for the effectiveness of leucine-rich repeats as protein-binding motifs. The structure can serve as a model for the interactions of other proteins containing leucine-rich repeats with their ligands.
authors.affiliation: Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas 75235-9050.
authors.forename: B
authors.initials: B
authors.lastname: Kobe
authors.forename: J
authors.initials: J
authors.lastname: Deisenhofer
mesh_terms: D000818:Animals; D002417:Cattle; D003196:Computer Graphics; D018360:Crystallography, X-Ray; D047908:Intracellular Signaling Peptides and Proteins; D007930:Leucine / Q000737:chemistry*; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*; D012259:Ribonuclease, Pancreatic / Q000037:antagonists & inhibitors / Q000737:chemistry*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; C066953:ribonuclease inhibitor, porcine; D012259:Ribonuclease, Pancreatic; D007930:Leucine