Also known as the CRD (cysteine rich domain), the C6 box in MuSK receptor. This domain of unknown function has been independently identified by several groups [1,2,3,4]. The domain contains 10 conserved cysteines.

1: The Frizzled CRD domain is conserved in diverse proteins including several receptor tyrosine kinases. Xu YK, Nusse R; Curr Biol 1998;8:405-406. PMID:9637908

2: The Wnt receptor CRD domain is also found in MuSK and related orphan receptor tyrosine kinases. Masiakowski P, Yancopoulos GD; Curr Biol 1998;8:407-407. PMID:9637909

3: Identification of a Frizzled-like cysteine rich domain in the extracellular region of developmental receptor tyrosine kinases. Saldanha J, Singh J, Mahadevan D Protein Sci 1998;7:1632-1635. PMID:9684897

4: The frizzled motif: in how many different protein families does it occur?. Rehn M, Pihlajaniemi T, Hofmann K, Bucher P; Trends Biochem Sci 1998;23:415-417. PMID:9852758