DOI: 10.1099/mgen.0.001093 ISSN:
AamA-mediated epigenetic control of genome-wide gene expression and phenotypic traits in Acinetobacter baumannii ATCC 17978
Jihye Yang, Yongjun Son, Mingyeong Kang, Woojun Park- General Medicine
Individual deletions of three genes encoding orphan DNA methyltransferases resulted in the occurrence of growth defect only in the aamA (encoding
Acinetobacter
A
denine M
ethylase A) mutant of
A
TTYAAA). Loss of Dam led to modulation of genome-wide gene expression, and several Dam-target sites including the promoter region of the trmD operon (rpsP, rimM, trmD, and rplS) were identified through our methylome and transcriptome analyses. AamA methylation also appeared to control the expression of many genes linked to membrane functions (lolAB, lpxO), replication (dnaA) and protein synthesis (trmD operon) in the strain ATCC 17978. Interestingly, cellular resistance against several antibiotics and ethidium bromide through functions of efflux pumps diminished in the absence of the aamA gene, and the complementation of aamA gene restored the wild-type phenotypes. Other tested phenotypic traits such as outer-membrane vesicle production, biofilm formation and virulence were also affected in the aamA mutant. Collectively, our data indicated that epigenetic regulation through AamA-mediated DNA methylation of novel target sites mostly in the regulatory regions could contribute significantly to changes in multiple phenotypic traits in