title: A family of regulatory genes associated with type II restriction-modification systems.
abstract: Restriction-modification systems must be regulated to avoid autorestriction and death of the host cell. An open reading frame (ORF) in the PvuII restriction-modification system appears to code for a regulatory protein from a previously unrecognized family. First, interruptions of this ORF result in a nonrestricting phenotype. Second, this ORF can restore restriction competence to such interrupted mutants in trans. Third, the predicted amino acid sequence of this ORF resembles those of known DNA-binding proteins and includes a probable helix-turn-helix motif. A survey of unattributed ORFs in 15 other type II restriction-modification systems revealed three that closely resemble the PvuII ORF. All four members of this putative regulatory gene family have a common position relative to the endonuclease genes, suggesting a common regulatory mechanism.
authors.affiliation: Department of Microbiology, Medical College of Ohio, Toledo 43699-0008.
authors.forename: T
authors.initials: T
authors.lastname: Tao
authors.forename: J C
authors.initials: JC
authors.lastname: Bourne
authors.forename: R M
authors.initials: RM
authors.lastname: Blumenthal
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D015280:DNA Restriction-Modification Enzymes / Q000235:genetics*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005786:Gene Expression Regulation; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D010957:Plasmids; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
chemical_list: D015280:DNA Restriction-Modification Enzymes; C025630:CAGCTG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific