A beta subtype methylase that recognizes the double-stranded sequence 5'-GANTC-3' and methylates non-modifed A-2 on the hemimethylated, post-replicative DNA (PubMed:12654995) (Probable). Functions only in the predivisional cell. Responsible for 5'-GANTC-3' methylation in the cell; remethylation of hemimethylated sites generated after replication fork passage occurs late in the predivisional cell, near completion of chromosome replication but prior to cell division. Constitutive expression of the methylase leads to morphologically aberrant cells as well as cells that have undergone additional chromosome replication. Contributes to the accurate cell-cycle control of DNA replication and cellular morphology (PubMed:8289276, PubMed:8577742). Opens a bubble in the DNA at the recognition site, allowing precise recognition of the sequence and ensuring enzyme specificity (By similarity). Can fully replace its ortholog in R.meliloti (PubMed:9294447). a 2'-deoxyadenosine in DNA + S-adenosyl-L-methionine = an N(6)-methyl-2'-deoxyadenosine in DNA + H(+) + S-adenosyl-L-homocysteine Homodimer. In synchonized cells transcribed (PubMed:8289276) and protein expressed (PubMed:8577742) only in predivisional cells (from 80 minutes) with a peak at 120 minutes, protein levels drop precipitously prior to cell division (at protein level). Transcribed from 80 minutes in synchronized cells. Has an N-terminal methyltransferase (MTase) domain linked to a C-terminal DNA-binding domain by a 10 residue linker. The MTase of one monomer recognizes, binds and modifies the target strand while C-terminal domain of the other monomer binds the non-target strand. Rapidly degraded by Lon protease prior to cell division. Essential, it cannot be disrupted. Belongs to the N(4)/N(6)-methyltransferase family.