Specificity versus Processivity in the Sequential Modification of DNA: A Study of DNA Adenine Methyltransferase

2018 ◽  
Vol 122 (3) ◽  
pp. 1112-1120 ◽  
Author(s):  
Itay Barel ◽  
Brigitte Naughton ◽  
Norbert O. Reich ◽  
Frank L. H. Brown
Keyword(s):  
Dna Adenine Methyltransferase

DNA methylation in Yersinia enterocolitica: role of the DNA adenine methyltransferase in mismatch repair and regulation of virulence factors

Microbiology ◽  
2005 ◽  
Vol 151 (7) ◽  
pp. 2291-2299 ◽  
Author(s):  
Stefan Fälker ◽  
M. Alexander Schmidt ◽  
Gerhard Heusipp
Keyword(s):  
Mismatch Repair ◽  
Yersinia Enterocolitica ◽  
Virulence Genes ◽  
Spontaneous Mutation ◽  
Gram Negative Bacteria ◽  
E Coli ◽  
Physiological Processes ◽  
Dna Adenine Methyltransferase

DNA adenine methyltransferase (Dam) plays an important role in physiological processes of Gram-negative bacteria such as mismatch repair and replication. In addition, Dam regulates the expression of virulence genes in various species. The authors cloned the dam gene of Yersinia enterocolitica and showed that Dam is essential for viability. Dam overproduction in Y. enterocolitica resulted in an increased frequency of spontaneous mutation and decreased resistance to 2-aminopurine; however, these effects were only marginal compared to the effect of overproduction of Escherichia coli-derived Dam in Y. enterocolitica, implying different roles or activities of Dam in mismatch repair of the two species. These differences in Dam function are not the cause for the essentiality of Dam in Y. enterocolitica, as Dam of E. coli can complement a dam defect in Y. enterocolitica. Instead, Dam seems to interfere with expression of essential genes. Furthermore, Dam mediates virulence of Y. enterocolitica. Dam overproduction results in increased tissue culture invasion of Y. enterocolitica, while the expression of specifically in vivo-expressed genes is not altered.

scholarly journals Undetectable levels of N6-methyl adenine in mouse DNA: Cloning and analysis of PRED28, a gene coding for a putative mammalian DNA adenine methyltransferase

FEBS Letters ◽  
2006 ◽  
Vol 580 (13) ◽  
pp. 3179-3184 ◽  
Author(s):  
David Ratel ◽  
Jean-Luc Ravanat ◽  
Marie-Pierre Charles ◽  
Nadine Platet ◽  
Lionel Breuillaud ◽  
...  
Keyword(s):  
Dna Cloning ◽  
Gene Coding ◽  
Dna Adenine Methyltransferase

scholarly journals Altered Ca2+ Regulation of Yop Secretion in Yersinia enterocolitica after DNA Adenine Methyltransferase Overproduction Is Mediated by Clp-Dependent Degradation of LcrG

2006 ◽  
Vol 188 (20) ◽  
pp. 7072-7081 ◽  
Author(s):  
Stefan Fälker ◽  
M. Alexander Schmidt ◽  
Gerhard Heusipp
Keyword(s):  
Yersinia Enterocolitica ◽  
Type Iii Secretion ◽  
Effector Proteins ◽  
Regulatory Mechanisms ◽  
Posttranslational Regulation ◽  
Bacterial Cells ◽  
Human Pathogen ◽  
Type Iii ◽  
Coordinated Expression ◽  
Dna Adenine Methyltransferase

ABSTRACT DNA methylation by the DNA adenine methyltransferase (Dam) interferes with the coordinated expression of virulence functions in an increasing number of pathogens. While analyzing the effect of Dam on the virulence of the human pathogen Yersinia enterocolitica, we observed type III secretion of Yop effector proteins under nonpermissive conditions. Dam alters the Ca2+ regulation of Yop secretion but does not affect the temperature regulation of Yop/Ysc expression. The phenotype is different from that of classical “Ca2+-blind” mutants of Yersinia, as Dam-overproducing (DamOP) strains still translocate Yops polarly into eukaryotic cells. Although transcription of the lcrGV and yopN-tyeA operons is slightly upregulated, LcrG is absent from lysates of DamOP bacteria, while the amounts of YopN and TyeA are not changed. We present evidence that clpXP expression increases after Dam overproduction and that the ClpP protease then degrades LcrG, thereby releasing a block in type III secretion. This is the first example of posttranslational regulation of type III secretion by the Clp protease and adds a new flavor to the complex regulatory mechanisms underlying the controlled release of effector proteins from bacterial cells.

scholarly journals YhdJ, a Nonessential CcrM-Like DNA Methyltransferase of Escherichia coli and Salmonella enterica

2007 ◽  
Vol 189 (11) ◽  
pp. 4325-4327 ◽  
Author(s):  
Sarah E. Broadbent ◽  
Roberto Balbontin ◽  
Josep Casadesus ◽  
Martin G. Marinus ◽  
Marjan van der Woude
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Dna Methyltransferase ◽  
Caulobacter Crescentus ◽  
Essential Gene ◽  
Gene Products ◽  
E Coli ◽  
Dna Adenine Methyltransferase

ABSTRACT The Caulobacter crescentus DNA adenine methyltransferase CcrM and its homologs in the α-Proteobacteria are essential for viability. CcrM is 34% identical to the yhdJ gene products of Escherichia coli and Salmonella enterica. This study provides evidence that the E. coli yhdJ gene encodes a DNA adenine methyltransferase. In contrast to an earlier report, however, we show that yhdJ is not an essential gene in either E. coli or S. enterica.

scholarly journals Overproduction of DNA Adenine Methyltransferase Alters Motility, Invasion, and the Lipopolysaccharide O-Antigen Composition of Yersinia enterocolitica

2007 ◽  
Vol 75 (10) ◽  
pp. 4990-4997 ◽  
Author(s):  
Stefan Fälker ◽  
Jennifer Schilling ◽  
M. Alexander Schmidt ◽  
Gerhard Heusipp
Keyword(s):  
Yersinia Enterocolitica ◽  
Human Pathogen ◽  
Cellular Functions ◽  
Bacterial Surface ◽  
O Antigen ◽  
Regulatory Processes ◽  
Enhanced Expression ◽  
Flagellum Biosynthesis ◽  
And Function ◽  
Dna Adenine Methyltransferase

ABSTRACT DNA adenine methyltransferase (Dam) not only regulates basic cellular functions but also interferes with the proper expression of virulence factors in various pathogens. We showed previously that for the human pathogen Yersinia enterocolitica, overproduction of Dam results in increased invasion of epithelial cells. Since invasion and motility are coordinately regulated in Y. enterocolitica, we analyzed the motility of a Dam-overproducing (DamOP) strain and found it to be highly motile. In DamOP strains, the operon encoding the master regulator of flagellum biosynthesis, flhDC, is upregulated. We show that the increased invasion is not due to enhanced expression of known and putative Y. enterocolitica invasion and adhesion factors, such as Inv, YadA, Ail, Myf fibrils, Pil, or Flp pili. However, overproduction of Dam no longer results in increased invasion for an inv mutant strain, indicating that Inv is necessary for increased invasion after overproduction of Dam. Since we show that overproduction of Dam results in an increased amount of rough lipopolysaccharide (LPS) molecules lacking O-antigen side chains, this implies that reduced steric hindrance by LPS might contribute to increased invasion by a Y. enterocolitica DamOP strain. Our data add an important new aspect to the various virulence-associated phenotypes influenced by DNA methylation in Y. enterocolitica and indicate that Dam targets regulatory processes modulating the composition and function of the bacterial surface.

scholarly journals Characterization of a DNA Adenine Methyltransferase Gene of Borrelia hermsii and Its Dispensability for Murine Infection and Persistence

PLoS ONE ◽  
2016 ◽  
Vol 11 (5) ◽  
pp. e0155798 ◽  
Author(s):  
Allison E. James ◽  
Artem S. Rogovskyy ◽  
Michael A. Crowley ◽  
Troy Bankhead
Keyword(s):  
Borrelia Hermsii ◽  
Methyltransferase Gene ◽  
Dna Adenine Methyltransferase

scholarly journals Analysis of Global Gene Expression and Double-Strand-Break Formation in DNA Adenine Methyltransferase- and Mismatch Repair-Deficient Escherichia coli

2005 ◽  
Vol 187 (20) ◽  
pp. 7027-7037 ◽  
Author(s):  
Jennifer L. Robbins-Manke ◽  
Zoran Z. Zdraveski ◽  
Martin Marinus ◽  
John M. Essigmann
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Mismatch Repair ◽  
Gene Expression Regulation ◽  
Replication Initiation ◽  
Double Strand Breaks ◽  
Recombinational Repair ◽  
Strand Breaks ◽  
E Coli ◽  
Dna Adenine Methyltransferase

ABSTRACT DNA adenine methylation by DNA adenine methyltransferase (Dam) in Escherichia coli plays an important role in processes such as DNA replication initiation, gene expression regulation, and mismatch repair. In addition, E. coli strains deficient in Dam are hypersensitive to DNA-damaging agents. We used genome microarrays to compare the transcriptional profiles of E. coli strains deficient in Dam and mismatch repair (dam, dam mutS, and mutS mutants). Our results show that >200 genes are expressed at a higher level in the dam strain, while an additional mutation in mutS suppresses the induction of many of the same genes. We also show by microarray and semiquantitative real-time reverse transcription-PCR that both dam and dam mutS strains show derepression of LexA-regulated SOS genes as well as the up-regulation of other non-SOS genes involved in DNA repair. To correlate the level of SOS induction and the up-regulation of genes involved in recombinational repair with the level of DNA damage, we used neutral single-cell electrophoresis to determine the number of double-strand breaks per cell in each of the strains. We find that dam mutant E. coli strains have a significantly higher level of double-strand breaks than the other strains. We also observe a broad range in the number of double-strand breaks in dam mutant cells, with a minority of cells showing as many as 10 or more double-strand breaks. We propose that the up-regulation of recombinational repair in dam mutants allows for the efficient repair of double-strand breaks whose formation is dependent on functional mismatch repair.

scholarly journals Histone H2B ubiquitylation and H3 lysine 4 methylation prevent ectopic silencing of euchromatic loci important for the cellular response to heat

2011 ◽  
Vol 22 (15) ◽  
pp. 2741-2753 ◽  
Author(s):  
Amy Leung ◽  
Ivelisse Cajigas ◽  
Peilin Jia ◽  
Elena Ezhkova ◽  
Jason H. Brickner ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cellular Response ◽  
Cell Wall Integrity ◽  
Silent Chromatin ◽  
Comparative Transcriptome ◽  
H3k4 Methylation ◽  
Histone H2b ◽  
Lysine Residues ◽  
Dna Adenine Methyltransferase ◽  
Active Genes

In Saccharomyces cerevisiae, ubiquitylation of histone H2B signals methylation of histone H3 at lysine residues 4 (K4) and 79. These modifications occur at active genes but are believed to stabilize silent chromatin by limiting movement of silencing proteins away from heterochromatin domains. In the course of studying atypical phenotypes associated with loss of H2B ubiquitylation/H3K4 methylation, we discovered that these modifications are also required for cell wall integrity at high temperatures. We identified the silencing protein Sir4 as a dosage suppressor of loss of H2B ubiquitylation, and we showed that elevated Sir4 expression suppresses cell wall integrity defects by inhibiting the function of the Sir silencing complex. Using comparative transcriptome analysis, we identified a set of euchromatic genes—enriched in those required for the cellular response to heat—whose expression is attenuated by loss of H2B ubiquitylation but restored by disruption of Sir function. Finally, using DNA adenine methyltransferase identification, we found that Sir3 and Sir4 associate with genes that are silenced in the absence of H3K4 methylation. Our data reveal that H2B ubiquitylation/H3K4 methylation play an important role in limiting ectopic association of silencing proteins with euchromatic genes important for cell wall integrity and the response to heat.

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