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p.436 left column bottom paragraph:"Using this metric, [investigators] find that the motifs of prokaryotic and eukaryotic TFs [transcription factors] are strikingly different (Figure 2, Tables S5–6 in the online supplementary material). The average information content of a prokaryotic motif I ˜ 23 bits is slightly above the required Imin = 22 bits, demonstrating that a single cognate site is generally sufficient to address a TF to a specific location in prokaryotes, though there still might be an overlap between the background and some weak but functional sites (Figure S1 in the online supplementary material). Although longer eukaryotic genomes require a TF to be more specific, [investigators] find that eukaryotic TFs are much less specific than bacterial TFs and do not contain sufficient information to find a cognate site among 10^9 decoys. The average information content of a multicellular eukaryotic motif is only I ˜ 12.1 bits, falling far below the Imin ˜ 30 bits required to provide a specific address in a eukaryotic genome (Figure 2). Yeast TF motifs have a mean information content of I = 13.8 bits, which is below the required Imin ˜ 24 bits, but represents a smaller information deficiency (Imin – I ˜ 10 bits) than that of the multicellular eukaryotes (Imin – I ˜ 18 bits)." See note beneath figure |