This motif is found on the scaffolding protein Axin which is a component of the beta-catenin destruction complex. It competes with the tumour suppressor adenomatous polyposis coli protein (APC) for binding to beta-catenin [1].

1: Crystal structure of a beta-catenin/axin complex suggests a mechanism for the beta-catenin destruction complex. Xing Y, Clements WK, Kimelman D, Xu W; Genes Dev. 2003;17:2753-2764. PMID:14600025