Transcription regulation of the type II restriction-modification system AhdI

Abstract Restriction–modification systems (R–M) are one of the antiviral defense tools used by bacteria, and those of the Type II family are composed of a restriction endonuclease (REase) and a DNA methyltransferase (MTase). Most entering DNA molecules are usually cleaved by the REase before they can be methylated by MTase, although the observed level of fragmented DNA may vary significantly. Using a model EcoRI R–M system, we report that the balance between DNA methylation and cleavage may be severely affected by transcriptional signals coming from outside the R–M operon. By modulating the activity of the promoter, we obtained a broad range of restriction phenotypes for the EcoRI R–M system that differed by up to 4 orders of magnitude in our biological assays. Surprisingly, we found that high expression levels of the R–M proteins were associated with reduced restriction of invading bacteriophage DNA. Our results suggested that the regulatory balance of cleavage and methylation was highly sensitive to fluctuations in transcriptional signals both up- and downstream of the R–M operon. Our data provided further insights into Type II R–M system maintenance and the potential conflict within the host bacterium.

Download Full-text

Species-Specific Type II Restriction-Modification System of Xylella fastidiosa Temecula1

Applied and Environmental Microbiology ◽

10.1128/aem.03034-09 ◽

2010 ◽

Vol 76 (12) ◽

pp. 4092-4095 ◽

Cited By ~ 17

Author(s):

Ayumi Matsumoto ◽

Michele M. Igo

Keyword(s):

Escherichia Coli ◽

Transformation Efficiency ◽

Xylella Fastidiosa ◽

Type Ii ◽

Modification System ◽

Restriction Modification System ◽

Species Specific ◽

Restriction Modification

ABSTRACT The transformation efficiency of Xylella fastidiosa can be increased by interfering with restriction by the strain-specific type II system encoded by the PD1607 and PD1608 genes. Here, we report results for two strategies: in vitro methylation using M.SssI and isolation of DNA from an Escherichia coli strain expressing the methylase PD1607.

Download Full-text

MmeI: a minimal Type II restriction-modification system that only modifies one DNA strand for host protection

Nucleic Acids Research ◽

10.1093/nar/gkn711 ◽

2008 ◽

Vol 36 (20) ◽

pp. 6558-6570 ◽

Cited By ~ 40

Author(s):

Richard D. Morgan ◽

Tanya K. Bhatia ◽

Lindsay Lovasco ◽

Theodore B. Davis

Keyword(s):

Type Ii ◽

Modification System ◽

Host Protection ◽

Restriction Modification System ◽

Minimal Type ◽

Dna Strand ◽

Restriction Modification

Download Full-text

Characterization of pECL18 and pKPN2: a proposed pathway for the evolution of two plasmids that carry identical genes for a Type II restriction-modification system

Molecular Genetics and Genomics ◽

10.1007/s00438-002-0644-y ◽

2002 ◽

Vol 267 (2) ◽

pp. 171-178 ◽

Cited By ~ 12

Author(s):

M. Zakharova ◽

I. Beletskaya ◽

M. Denjmukhametov ◽

T. Yurkova ◽

L. Semenova ◽

...

Keyword(s):

Type Ii ◽

Modification System ◽

Restriction Modification System ◽

Restriction Modification

Download Full-text

Comparative genomics of the Pasteurella multocida toxin

Genome ◽

10.1139/gen-2020-0176 ◽

2021 ◽

Author(s):

Shivakumara Siddaramappa

Keyword(s):

Pasteurella Multocida ◽

Capsular Polysaccharide ◽

Bacterial Species ◽

Atrophic Rhinitis ◽

Type Ii ◽

Nucleotide Polymorphisms ◽

Modification System ◽

Restriction Modification System ◽

Heat Labile ◽

Restriction Modification

Pasteurella multocida is a zoonotic pathogen whose genetic heterogeneity is well known. Five serogroups and 16 serotypes of P. multocida have been recognized thus far based on capsular polysaccharide typing and lipopolysaccharide typing, respectively. Progressive atrophic rhinitis in domestic pigs is caused by P. multocida strains containing toxA, which encodes a heat-labile toxin. In this study, by comparative analyses of the genomes of many strains, it has been shown that toxA is sparsely distributed in P. multocida. Furthermore, full-length homologs of P. multocida toxA were found only in two other bacterial species. It has also been shown that toxA is usually associated with a prophage. Among the toxA-containing prophages that were compared, an operon putatively encoding a type II restriction-modification system was present only in strains LFB3, HN01, and HN06. These results indicate that the selection and maintenance of the heat-labile toxin and the type II restriction-modification system are evolutionarily less favorable among P. multocida strains. Phylogenetic analysis using the alignment- and parameter-free method CVTree3 showed that deduced proteome sequences can be used as effectively as whole/core genome single nucleotide polymorphisms to group P. multocida strains in relation to their serotypes and/or genotypes.

Download Full-text