Information related to 1766 E. coli promoters annotated in the Ecocyc Database  (Version 12.5, updated on 8th October, 2008) (Keseler et al 2005) was downloaded.  For 176 of them either the transcription direction or transcription start site (TSS) information was not available. In addition, the TSS for the first promoter, PM00249 is at position 148 and does not have a 500 bp sequence upstream of the TSS. Hence, only 1590 promoters were considered for inclusion in the Ecoprom database.