Sorry about my previous reply. The question was for DNA sequence
motifs and my answer was for protein sequence motifs.
The TFD database has several DNA sequence motifs found in yeast,
however it is a Transcription Factor Database and would lack some of
the types of sequence motifs that the original message was requesting.
TFD is available as flat files, in a variety of formats, via anonymous
ftp from ncbi.nlm.nih.gov look in the repository/TFD directory. TFD is
the creation of D. Ghosh, NCBI.