The Human Transcription Factors

In the Results, the sentence reading ‘‘Among the 1,107 proteins with a known motif, less than 2% (19) lack a canonical DBD, with only 6 of 69 such proteins having an in vitro derived motif—the other 13 are based on experiments such as ChIP-seq and thus may describe binding through a cofactor’’ created ambiguity about how the different subsets of proteins were classified. To clarify this point, the sentence has been revised to read ‘‘Among the 1,107 TFs with a known motif, less than 2% (19) are among the 69 putative TFs that lack a canonical DBD. Indeed, among the 69, it appears that only a small proportion have been analyzed in detail for sequence specificity, while the inclusion of the rest of the 69 proteins among TFs is based on other lines of evidence such as known individual genomic target sites, or existence of a DNA-protein co-structure. Only 6 of the 19 motifs for the 69 noncanonical TFs have been derived in vitro, while the other 13 motifs are based on experiments such as ChIP-seq, and thus could potentially describe binding through a cofactor.’’