InterPro domain: IPR032675

This superfamily represents a leucine-rich repeat (LRR), right-handed beta-alpha superhelix domain, such as that found in bacterial invasion protein internalin [ 1 ] or in the L domain from members of the epidermal growth-factor receptor (EGFR) family [ 2 ].

Leucine-rich repeats (LRR) consist of 2-45 motifs of 20-30 amino acids in length that generally folds into an arc or horseshoe shape [ 3 ]. LRRs occur in proteins ranging from viruses to eukaryotes, and appear to provide a structural framework for the formation of protein-protein interactions [ 4 , 5 ].Proteins containing LRRs include tyrosine kinase receptors, cell-adhesion molecules, virulence factors, and extracellular matrix-binding glycoproteins, and are involved in a variety of biological processes, including signal transduction, cell adhesion, DNA repair, recombination, transcription, RNA processing, disease resistance, apoptosis, and the immune response [ 6 ].

1. Thermodynamically reengineering the listerial invasion complex InlA/E-cadherin. Proc. Natl. Acad. Sci. U.S.A. 104, 13960-5
2. Crystal structure of the first three domains of the type-1 insulin-like growth factor receptor. Nature 394, 395-9
3. Structural principles of leucine-rich repeat (LRR) proteins. Proteins 54, 394-403
4. The leucine-rich repeat as a protein recognition motif. Curr. Opin. Struct. Biol. 11, 725-32
5. A leucine-rich repeat peptide derived from the Drosophila Toll receptor forms extended filaments with a beta-sheet structure. FEBS Lett. 291, 87-91
6. slit: an extracellular protein necessary for development of midline glia and commissural axon pathways contains both EGF and LRR domains. Genes Dev. 4, 2169-87