Bacterial DNA Methylation and Methylomes.
Formation of C5-methylcytosine, N4-methylcytosine, and N6-methyladenine in bacterial genomes is postreplicative and involves transfer of a methyl group from S-adenosyl-methionine to a base embedded in a specific DNA sequence context. Most bacterial DNA methyltransferases belong to restriction-modification systems; in addition, "solitary" or "orphan" DNA methyltransferases are frequently found in the genomes of bacteria and phage. Base methylation can affect the interaction of DNA-binding proteins with their cognate sites, either by a direct effect (e.g., steric hindrance) or by changes in DNA topology. In both Alphaproteobacteria and Gammaproteobacteria, the roles of DNA base methylation are especially well known for N6-methyladenine, including control of chromosome replication, nucleoid segregation, postreplicative correction of DNA mismatches, cell cycle-coupled transcription, formation of bacterial cell lineages, and regulation of bacterial virulence. Technical procedures that permit genome-wide analysis of DNA methylation are nowadays expanding our knowledge of the extent, evolution, and physiological significance of bacterial DNA methylation.
Departamento de Genética, Universidad de Sevilla, Apartado 1095, Seville, 41080, Spain. casadesus@us.es.
Josep
J
Casadesús
D044503:5-Methylcytosine / Q000737:chemistry* / Q000378:metabolism; D000225:Adenine / Q000737:chemistry / Q000378:metabolism; D000241:Adenosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000235:genetics; D020561:Alphaproteobacteria / Q000235:genetics; D019070:Cell Lineage / Q000235:genetics; D019175:DNA Methylation / Q000235:genetics*; D004261:DNA Replication / Q000235:genetics; D020563:Gammaproteobacteria / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D016680:Genome, Bacterial
D044503:5-Methylcytosine; C010223:N-methyladenosine; D000225:Adenine; D000241:Adenosine