title: A novel restriction-modification system from Xanthomonas campestris pv. vesicatoria encodes a m4C-methyltransferase and a nonfunctional restriction endonuclease.
abstract: A novel restriction-modification (R-M) system, designated as xveIIRM, from chromosomal DNA of the Xanthomonas campestris pv. vesicatoria strain 7-1 (Xcv7-1) was cloned and characterized. The xveIIRM genes involved in this R-M system are aligned in a tail-to-tail orientation and overlapped by 12 base pairs. XveII methyltransferase gene could encode a 299-amino acid protein (M.XveII) with an estimated mass of 33.7 kDa and was classified to be a member of beta-class of m4C-MTase. M.XveII methylates the second cytosine of the 5'-CCCGGG-3' recognition sequence. The predicted amino acid sequence of the intact XveII endonuclease shared 41.9% identity with SmaI. However, a premature TAA translation termination codon was found in the open reading frame of xveIIR and expected to encode an 18.3 kDa truncated protein. The sequence data are consistent with observation of this study that no SmaI-like restriction activity could be detected in the cell extract of Xcv7-1.
authors.affiliation: Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Yu-Jen
authors.initials: YJ
authors.lastname: Yu
authors.forename: Ming-Te
authors.initials: MT
authors.lastname: Yang
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D015139:Blotting, Southern; D002876:Chromosomes, Bacterial; D003001:Cloning, Molecular; D015280:DNA Restriction-Modification Enzymes / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D015257:DNA-Cytosine Methylases / Q000235:genetics*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics; D023061:Gene Order; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D016959:Xanthomonas campestris / Q000201:enzymology* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D015280:DNA Restriction-Modification Enzymes; D004269:DNA, Bacterial; D015257:DNA-Cytosine Methylases; C025651:CCCGGG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific