A putative hsdMSR locus in E2348/69. Large open arrows indicate hsdM, hsdS, and hsdR open reading frames. Numbers at left and right indicate positions in the unannotated E2348/69 genome. Primers used to construct a ΔhsdR allele are indicated at bottom of figure. The location of the hsdR deletion that removes the conserved helicase and ATP binding domains is indicated by a shaded box and an inverted triangle. aa, amino acid; nt, nucleotides.