TABLE 1.

Nonmethylated GATC sites in the E. coli K-12 chromosome

^aLocation in the E. coli K-12 strain MG1655 chromosome. Analyses were carried out using Pattern Search and Fragment Viewer in ColiBase (http://colibase.bham.ac.uk/).

^bGATC sites protected from methylation are shown in boldface, with 9 base pairs of flanking sequence on each side.

^cThe distance from the “G” in GATC to the “A” of the start codon for a particular gene is shown in base pairs. For regions where divergent transcription occurs, the distances to both genes/open reading frames is shown in base pairs.

^dRegulatory proteins known to protect methylation of a specific GATC site, based on in vitro methylation protection, are shown in boldface. Other potential methylation-blocking proteins are shown based on indirect data such as presence of a consensus regulatory protein binding site, observation of protein binding near the GATC sequence, or increased methylation of a GATC site observed in a regulatory mutant of E. coli.