Figure 5. Comparison ofXCorr scores from Tide and from two versions of SEQUEST.
From two different data sets (yeast and worm), 100 spectra were selected at random for analysis by SEQUEST and by Tide. Searches were performed using a database of tryptic peptides from the corresponding organism, allowing up to two phosphorylations per peptide at occurrences of STY. The figure includes the top five PSMs per spectrum, as reported by SEQUEST. For each PSM, we plot the SEQUEST XCorr versus the XCorr computed by Tide. In the case of the bottom figures, we plot the SEQUEST 1993 XCorr scores against those computed by SEQUEST 2009.