title: Cloning and sequences of the genes encoding the CfrBI restriction-modification system from Citrobacter freundii.
abstract: The genes encoding the CfrBI restriction and modification (R-M) systems from Citrobacter freundii and recognizing the sequence 5'-CCWWGG-3' (W = A or T) were cloned in Escherichia coli McrBC- cells. The nucleotide (nt) sequences of the genes were determined. Two large open reading frames were found. Deletion analysis showed that one of them [1128 nt coding for 376 amino acids (aa)] corresponds to a methyltransferase (MTase)-encoding gene and the other (1065 nt coding for 355 aa) to a restriction endonuclease-encoding gene. The genes are oriented divergently and separated by 76 bp. A CfrBI site (5'-m4CCATGG) was found in the intergenic region of the cfrBIRM genes. Analysis of the deduced aa sequence of M.CfrBI made it possible to determine the typical features of a m4C-specific MTase. Limited homology between the M.CfrBI and R.CfrBI proteins was also found.
authors.affiliation: Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region.
authors.forename: M V
authors.initials: MV
authors.lastname: Zakharova
authors.forename: A N
authors.initials: AN
authors.lastname: Kravetz
authors.forename: I V
authors.initials: IV
authors.lastname: Beletzkaja
authors.forename: A V
authors.initials: AV
authors.lastname: Repyk
authors.forename: A S
authors.initials: AS
authors.lastname: Solonin
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D016971:Citrobacter freundii / Q000201:enzymology / Q000235:genetics*; D003001:Cloning, Molecular; D015280:DNA Restriction-Modification Enzymes / Q000737:chemistry / Q000235:genetics*; D005798:Genes, Bacterial; D008745:Methylation; D008969:Molecular Sequence Data; D008970:Molecular Weight; D015183:Restriction Mapping; D016415:Sequence Alignment
chemical_list: D015280:DNA Restriction-Modification Enzymes