Open AccessDNA methylation in mycobacteria: Absence of methylation at GATC (Dam) and CCA/TGG (Dcm) sequences
Author(s) -
Hemavathy Kirugaval C.,
Nagaraja Valakunja
Publication year - 1995
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.1995.tb00159.x
Subject(s) - isoschizomer , methyltransferase , biology , mycobacterium smegmatis , methylation , dna methylation , genomic dna , dna , restriction enzyme , genetics , mycobacterium , microbiology and biotechnology , mycobacterium tuberculosis , gene , bacteria , tuberculosis , gene expression , medicine , pathology
The presence of 6‐methyladenine and 5‐methylcytosine at Dam (GATC) and Dcm (CCA/TGG) sites in DNA of mycobacterial species was investigated using isoschizomer restriction enzymes. In all species examined, Dam and Dcm recognition sequences were not methylated indicating the absence of these methyltransferases. On the other hand, high performance liquid chromatographic analysis of genomic DNA from Mycobacterium smegmatis and Mycobacterium tuberculosis showed significant levels of 6‐methyladenine and 5‐methylcytosine suggesting the presence of DNA methyltransferases other than Dam and Dcm. Occurrence of methylation was also established by a sensitive genetic assay.