@article{mbs:/content/journal/micro/10.1099/mic.0.28624-0, author = "Banerjee, Sanjib and Chowdhury, Rukhsana", title = "An orphan DNA (cytosine-5-)-methyltransferase in Vibrio cholerae", journal= "Microbiology", year = "2006", volume = "152", number = "4", pages = "1055-1062", doi = "https://doi.org/10.1099/mic.0.28624-0", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.28624-0", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "Vsr, very short patch repair (endonuclease)", keywords = "VSP, very short patch (repair system)", keywords = "R-M, restriction-modification", keywords = "AdoMet, S-adenosyl methionine", keywords = "m5C, 5-methyl cytosine", keywords = "MTase, methyltransferase", abstract = "5-Methyl cytosine (m5C) was detected in genomic DNA of the enteric pathogen Vibrio cholerae by HPLC analysis and immunoblotting with m5C-specific antibody. Although cleavage with the restriction endonuclease EcoRII revealed the absence of a Dcm homologue in V. cholerae, analysis of the genome sequence indicated the presence of a gene, designated in this study as vchM, which encodes a DNA (cytosine-5-)-methyltransferase (m5C-MTase) designated M.Vch. M.Vch is not associated with a restriction endonuclease or a mismatch very short patch repair (Vsr)-like endonuclease and is hence an ‘orphan’ or solitary MTase, although analysis of a phylogenetic tree indicated that related cytosine MTases are all components of restriction-modification systems. M.Vch recognizes and methylates the first 5′ C in the degenerate sequence 5′-RCCGGY-3′. RT-PCR analysis suggested that vchM gene expression is increased during the stationary phase of growth. During stationary phase, the spontaneous mutation frequency in the V. cholerae wild-type strain was significantly higher than in the corresponding vchM mutant strain, suggesting that the presence of M.Vch and the absence of a very short patch (VSP) repair-like system imposes upon V. cholerae a mutator phenotype.", }