| Type: | Repeat | Name: | Tetratricopeptide repeat |
| Description: | The tetratrico peptide repeat region (TPR) is a structural motif present in a wide range of proteins [, , ]. It mediates protein-protein interactions and the assembly of multiprotein complexes []. The TPR motifconsists of 3-16 tandem-repeats of 34 amino acids residues, although individual TPR motifs can be dispersed in the protein sequence. Sequence alignment of the TPR domains reveals aconsensus sequence defined by a pattern of small and large amino acids. TPR motifs have been identified in various different organisms, ranging from bacteria to humans. Proteins containingTPRs are involved in a variety of biological processes, such as cell cycle regulation, transcriptional control, mitochondrial and peroxisomal protein transport, neurogenesis andprotein folding.The X-ray structure of a domain containing three TPRs from protein phosphatase 5 revealed that TPR adopts a helix-turn-helix arrangement, with adjacent TPR motifs packing in a parallelfashion, resulting in a spiral of repeating anti-parallel alpha-helices []. The two helices are denotedhelix A and helix B. The packing angle between helix A and helix B is ~24 degrees within a single TPR and generates a right-handed superhelical shape. Helix A interacts with helix B andwith helix A' of the next TPR. Two protein surfaces are generated: the inner concave surface is contributed to mainly by residue on helices A, and the other surface presents residues from bothhelices A and B. | Short Name: | TPR_repeat |
