title: GATC-specific restriction and modification systems in treponemes.
abstract: OBJECTIVE
  To investigate the presence of GATC-specific modification and restriction activities in rumen isolates of Treponema sp.
  
  
  METHODS
  The presence of N6-methyladenine within GATC (Dam) sequences was analysed using isoschizomeric restriction endonucleases having different sensitivities to the methylation of the target sequence. A fast screening method was used for testing of site-specific endonuclease activities directly in crude cell extracts. Three out of six rumen isolates of Treponema sp. showed restriction activities. Restriction endonucleases were further purified by Heparin-Sepharose chromatography. Using PCR and specific primers, no sequence homologous to the T. pallidum dam gene was found.
  
  
  CONCLUSIONS
  Three rumen treponemal strains were documented to possess MboI isoschizomeric restriction-modification systems.
  
  
  CONCLUSIONS
  This is the first report on restriction activity in rumen treponemes.
authors.affiliation: Faculty of Science, Institute of Chemistry, P. J. Safarik University, Moyzesova, Kosice, Slovakia. piknova@saske.sk
authors.forename: M
authors.initials: M
authors.lastname: Piknova
authors.forename: P
authors.initials: P
authors.lastname: Pristas
authors.forename: P
authors.initials: P
authors.lastname: Javorsky
authors.forename: A
authors.initials: A
authors.lastname: Kasperowic
authors.forename: T
authors.initials: T
authors.lastname: Michalowski
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000032:analysis; D000818:Animals; D001483:Base Sequence; D002846:Chromatography, Affinity; D015280:DNA Restriction-Modification Enzymes / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012417:Rumen / Q000382:microbiology; D012685:Sepharose / Q000031:analogs & derivatives*; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D014208:Treponema / Q000201:enzymology* / Q000302:isolation & purification
chemical_list: D000225:Adenine; D015280:DNA Restriction-Modification Enzymes; D015252:Deoxyribonucleases, Type II Site-Specific; D012685:Sepharose; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); C037405:heparin-sepharose; C058693:Dam methyltransferase; C024405:GATC-specific type II deoxyribonucleases; C000730567:6-methyladenine