title: Characterization of the type IV restriction modification system BspLU11III from Bacillus sp. LU11.
abstract: We report the characterization and cloning of the genes for an unusual type IV restriction-modification system, BspLU11III, from Bacillus sp. LU11. The system consists of two methyltransferases and one endonuclease, which also possesses methyltransferase activity. The three genes of the restriction-modification system, bsplu11IIIMa, bsplu11IIIMb and bsplu11IIIR, are closely linked and tandemly arranged. The corresponding enzymes recognize the dsDNA sequence 5'-GGGAC-3'/5'-GTCCC-3', with M.BspLU11IIIa modifying the A (underlined) of one strand and M.BspLU11IIIb the inner C (underlined) of the other strand. R.BspLU11III has both endonuclease and adenine-specific methyltransferase activities and is able to protect the DNA against cleavage by itself. In contrast to all type IV restriction-modification systems described so far, which have only one adenine-specific methyltransferase, BspLU11III is the first type IV restriction-modification system that includes two methyltransferases, one of them being cytosine specific.
authors.affiliation: Institute of Protein Research, 142292 Pushchino, Moscow Region, Russia.
authors.forename: K
authors.initials: K
authors.lastname: Lepikhov
authors.forename: A
authors.initials: A
authors.lastname: Tchernov
authors.forename: L
authors.initials: L
authors.lastname: Zheleznaja
authors.forename: N
authors.initials: N
authors.lastname: Matvienko
authors.forename: J
authors.initials: J
authors.lastname: Walter
authors.forename: T A
authors.initials: TA
authors.lastname: Trautner
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D003001:Cloning, Molecular; D019175:DNA Methylation; D015280:DNA Restriction-Modification Enzymes / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015257:DNA-Cytosine Methylases / Q000235:genetics* / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000235:genetics* / Q000378:metabolism
chemical_list: D015280:DNA Restriction-Modification Enzymes; D004269:DNA, Bacterial; D015257:DNA-Cytosine Methylases; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); C080591:endodeoxyribonuclease BspLU11I; D015252:Deoxyribonucleases, Type II Site-Specific