PSSMs from the HOMER motif database
A data frame containing the PSSMs ('A', 'C', 'G' and 'T' columns), with an additional column 'motif' containing the motif name.
References
Heinz S, Benner C, Spann N, Bertolino E et al. Simple Combinations of Lineage-Determining Transcription Factors Prime cis-Regulatory Elements Required for Macrophage and B Cell Identities. Mol Cell 2010 May 28;38(4):576-589. PMID: 20513432