title: The replicative origin of the E. coli chromosome binds to cell membranes only when hemimethylated.
abstract: DNA from the E. coli replicative origin binds with high affinity to outer membrane preparations. Specific binding regions are contained within a 463 bp stretch of origin DNA between positions -46 and +417 on the oriC map. This region of DNA contains an unusually high number of GATC sites, the recognition sequence for the E. coli DNA adenine methylase. We show here that oriC DNA binds to membrane only when it is hemimethylated. The E. coli chromosomal origin is hemimethylated for 8-10 min after initiation of replication, and origin DNA binds to membranes only during this time period. Based on these results, we propose a speculative model for chromosome segregation in E. coli.
authors.affiliation: Department of Molecular Biology and Microbiology Tufts University Health Sciences Campus, Boston, Massachusetts 02111.
authors.forename: G B
authors.initials: GB
authors.lastname: Ogden
authors.forename: M J
authors.initials: MJ
authors.lastname: Pratt
authors.forename: M
authors.initials: M
authors.lastname: Schaechter
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D002850:Chromatography, Gel; D002876:Chromosomes, Bacterial / Q000378:metabolism*; D004261:DNA Replication; D004262:DNA Restriction Enzymes; D004269:DNA, Bacterial / Q000096:biosynthesis / Q000378:metabolism*; D015252:Deoxyribonucleases, Type II Site-Specific; D004587:Electrophoresis, Agar Gel; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D008745:Methylation; D009693:Nucleic Acid Hybridization; D010957:Plasmids
chemical_list: D004269:DNA, Bacterial; D004262:DNA Restriction Enzymes; C028678:CYCGRG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific