Fig. 3

Assessment of protein sequence similarity as a predictor of TRN transfer method accuracy. The plots show the PR-AUC of bidirectional transfers between 143 (66 LexA, 77 Fur) TF-specific species pairs using motif-based (direct transfer) and transfer-based methods (ortholog mode) as a function of TF protein sequence similarity. The results obtained with a permutation of the target motif are shown for comparison. The x-axis denotes protein similarity as the BLOSUM62 score of the ungapped pair-wise alignment between reference and target TF protein sequences. PR-AUC values are normalized to the respective AUC of the known target TF-binding motif to compensate for the decreased search efficiency of low information content motifs. Spearman correlation coefficients (ρ) of PR-AUC with protein similarity are shown for each case