Recognizes the double-stranded sequence 5'-GACGAG-3' and methylates A-5, yielding m6A. m6A methylation functions as a transcriptional modifier, promoting transcription of a number of genes (at least scpA, hbs, rnhC, yumC and zapA). One studied mechanism is via transcriptional repressor ScoC (also called hpr) which binds to non-methylated scpA promoter; when the m6A target is methylated ScoC no longer binds and scpA transcription is up-regulated. Other mechanisms for gene expression regulation probably exist. Binds DNA with and without the target sequence. Although it resembles a restriction-modification system, it does not have detectable endonuclease activity under tested conditions (PubMed:32324221). A gamma subtype methylase (PubMed:12654995). a 2'-deoxyadenosine in DNA + S-adenosyl-L-methionine = an N(6)-methyl-2'-deoxyadenosine in DNA + H(+) + S-adenosyl-L-homocysteine No visible growth defects, no A-5 methylation of 5'-GACGAG-3' in strains NCIMB 3610 or PY79. Decreased promoter activity for promoters with the target sequence very close to the -35 SigA-binding box (scpA, hbs, rnhC, yumC and zapA). Between 94.7% and 99.7% of the 5'-GACGAG-3' motifs are methylated on A-5 in strain NCIMB 3610 and PY79 respectively. The sites are enriched on the left chromosomal arm. Belongs to the methyltransferase superfamily.