Validation of the signal detection algorithm. (A) Distribution of number of TA-like signals identified in randomly shuffled TIS upstream sequences retaining dinucleotide frequency of 7769 genes for the S. coelicolor A3(2) genome. (B) Simulative test for the statistical significance of TA-like signals detected by the algorithm. X axis is the number of TA-led genes detected in the real data. Y axis shows the maximum number of TA-led genes detected in 1000 shuffled datasets. All points are remarkably below the Y = × line. All 206 bacterial genomes detected with leaderless genes have been analyzed.