Does YMF search for TRANSFAC motifs ?
No, YMF is intended to discover novel binding sites. It was not designed to find instances of known motifs (from TRANSFAC or SCPD or any other motif database) in input sequences. It may happen that a motif discovered by YMF is very similar to a motif from one of the databases, but that will be because the motif is over-represented in the input sequences, and not because it is present in a database.