Figure 3
Changes in the distribution of blastx and tblastx hits as a function of E-value threshold. The proportion of top-scoring matches to viruses (including bacteriophages), prokaryotes, or eukaryotes is plotted as a function of the E-value threshold for blastx (left panel) or tblastx (right panel). The vertical dashed line represents the frequently used threshold of 10-3, beyond which hits would not be considered significant (pink shaded region). The solid line in each graph shows the cumulative percentage of sequences that lie at or below a given E-value threshold.