Sequence alignment of the C-terminal domains of the FZDs and SMO. The C-terminal domains from ten FZDs (FZD1–10) and SMO were aligned using ClustalW (http://www.ebi.ac.uk/Tools/msa/clustalw2/). The conserved KTXXXW motif is highlighted in bold. The sequence used in the study is shown with a box. The protein sequences were obtained from protein knowledgebase (http://www.uniprot.org) with the following accession numbers: FZD1, Q9UP38; FZD2, Q14332; FZD3, Q9NPG1; FZD4, Q9ULV1; FZD5, Q13467; FZD6, O60353; FZD7, O75084; FZD8, Q9H461; FZD9, O00144; FZD10, Q9ULW2; SMO, Q99835. For clarity, only a partial sequence from the C-terminus of SMO is shown.