title: Shaping the genome--restriction-modification systems as mobile genetic elements.
abstract: A restriction enzyme gene is often linked to a modification methylase gene the role of which is to protect a recognition site on DNA from breakage by the former. Loss of some restriction-modification gene complexes leads to cell death through restriction breakage in the genome. Their behavior as genomic parasites/symbionts may explain the distribution of restriction sites and clarify certain aspects of bacterial recombination repair and mutagenesis. A comparison of bacterial genomes supports the hypothesis that restriction-modification gene complexes are mobile elements involved in various genome rearrangements and evolution.
authors.affiliation: Institute of Medical Science, University of Tokyo, Shirokanedai, 108-8639, Japan. ikobaya@ims.u-tokyo.ac.jp
authors.forename: I
authors.initials: I
authors.lastname: Kobayashi
authors.forename: A
authors.initials: A
authors.lastname: Nobusato
authors.forename: N
authors.initials: N
authors.lastname: Kobayashi-Takahashi
authors.forename: I
authors.initials: I
authors.lastname: Uchiyama
mesh_terms: D001419:Bacteria / Q000201:enzymology / Q000235:genetics; D004262:DNA Restriction Enzymes / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D005798:Genes, Bacterial / Q000235:genetics*; D016680:Genome, Bacterial; D006790:Host-Parasite Interactions / Q000235:genetics; D020071:Interspersed Repetitive Sequences / Q000235:genetics*; D016296:Mutagenesis / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics
chemical_list: D004262:DNA Restriction Enzymes