Tetratricopeptide Repeat Domain Protein 28 (TTC28)

TTC28 Contains 28 TPR repeats. The tetratricopeptide repeat (TPR) is a structural motif. It consists in a degenerate 34 amino acid sequence motif identified in a wide variety of proteins. It is found in tandem arrays of 3–16 motifs, which form scaffolds to mediate protein–protein interactions and often the assembly of multiprotein complexes. TPR-containing proteins include the anaphase-promoting complex (APC) subunits cdc16, cdc23 and cdc27, the NADPH oxidase subunit p67-phox, hsp90-binding immunophilins, transcription factors, the PKR protein kinase inhibitor, the major receptor for peroxisomal matrix protein import PEX5 and mitochondrial import proteins. The structure solved by X-ray crystallography by Das and colleagues showed that the TPR sequence motif was composed of a pair of antiparallel alpha helices.