Hi Bruno, The significance cutoff you choose all depends on what you are trying to do. A more stringent cutoff will likely have a higher proportion of true functional sites, but this will come at the cost of missing true sites that might not be as strongly conserved. Likewise, a less stringent cutoff will capture more true binding sites, but will also introduce more false positives. Regardless, it is important to keep in mind that these are simply predictions based on conserved sequences.
As for converting from Z-scores to P-values, this can be achieved using the normal cumulative probability distribution. This is implemented in most statistical packages like R, or you can use a lookup table like one: http://www.epatric.com/documentation/statistics/z-score_table.html Matt (re-post) Bruno Pardo wrote: > Hello, > > I am using the UCSC genome Browser to find > informations about transcription factors binding sites. > > I retrieved the Data from the tfbsConsSites Table > (group regulation, track TFBS Conserved). > > I would like to know if the sites with a z-score <2.33 > can be considered as sufficiently significant and > how to calculate the pvalue from the z-score. > > Best Regards > > Bruno Pardo > _______________________________________________ > Genome maillist - [email protected] > https://lists.soe.ucsc.edu/mailman/listinfo/genome > _______________________________________________ Genome maillist - [email protected] https://lists.soe.ucsc.edu/mailman/listinfo/genome
