I have approximately 2000 SNPs and I would like to know if some of the SNPs fall into TFB sites. My idea was to you homer as it is quite simple and needs only bed-file of my SNPs (actually of chip-seq peaks but I guess it is not a problem if I have given it the positions of my snps) as an input and region size. However, for 2000 SNPs and region size 50 I got only 3 known motifs.
Is there any other tool so that I could compare my results?
2 answers
You could use the Ensembl VEP. Run your list of SNPs against the database then filter for the consequence TF_binding_site_variant.
You could use jaspar2meme to convert JASPAR motif data into a form usable with FIMO.
Once you have constructed a list of whole-genome TFBS at the desired FIMO threshold (say, 1e-4 or 1e-5), you could use bedmap to associate those TFBS with your SNPs:
$ bedmap --echo --echo-map-id-uniq --skip-unmapped tfbs.bed snps.bed
which prints a list of TFBSs and their associated SNP IDs, where there are associations.
You could also go the other direction, and get the list of SNP positions and associated TFBSs:
$ bedmap --echo --echo-map --skip-unmapped snps.bed tfbs.bed
Depends on how you want to do the association.
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