shown to be necessary and sufficient
for Wnt ligand binding to the
surface of expressing cells [2].
We performed a database search
for the presence of additional
proteins containing the CRD motif.
A profile of the CRD was made by
BLOCK MAKER [3] at the National
Center for Biotechnology
Information. The cobbler sequences
of the blocks were subsequently
used to perform a PSI-BLAST search
[4] against the non-redundant
protein database. By iterating
PSI-BLAST twice more, a variety of
proteins were found to share the
CRD motif with high significance
(E < 0.01). An alignment of the