<p>Leucine-rich repeats (LRR, see <db_xref db="INTERPRO" dbkey="IPR001611"/>) consist of 2-45 motifs of 20-30 amino acids in length that generally folds into an arc or horseshoe shape [<cite idref="PUB00017058"/>]. LRRs occur in proteins ranging from viruses to eukaryotes, and appear to provide a structural framework for the formation of protein-protein interactions [<cite idref="PUB00007147"/>]. 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.</p><p>LRRs are often flanked by cysteine-rich domains: an N-terminal LRR domain (<db_xref db="INTERPRO" dbkey="IPR000372"/>) and a C-terminal LRR domain. This entry represents the C-terminal LRR domain. </p>