To get a global view of PT modification’s function in ∆dam mutant, we did an RNA-seq to compare the gene expression change after dam knocks out and test whether PT could restore the changes. Overall design: We selected mid-log-phase cultures of E.coli ∆dam mutant with or without expressing dndBCDE, to perform RNAseq analysis with wild-type E.coli BW25113 as the reference.