Characterization of the mcrBC region of Escherichia coli K-12 wild-type and mutant strains

Krüger, Torsten; Grund, C; Wild, Carola; Noyer-Weidner, Mario

doi:10.1016/0378-1119(92)90700-y

Cited by 28 publications

(22 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These proteins share the same amino acid sequence except for 161 amino acids at the N-terminus that are missing in McrB S . 93,95–98 McrB L and McrC are sufficient for methyl-DNA cleavage activity, 99 and McrB S is involved in activity modulation. 100,101 …”

Section: Mcrbc a Methyl-specific Dna Endonuclease (Type IV Restrictimentioning

confidence: 99%

Conflicts Targeting Epigenetic Systems and Their Resolution by Cell Death: Novel Concepts for Methyl-Specific and Other Restriction Systems

2010

View full text Add to dashboard Cite

Epigenetic modification of genomic DNA by methylation is important for defining the epigenome and the transcriptome in eukaryotes as well as in prokaryotes. In prokaryotes, the DNA methyltransferase genes often vary, are mobile, and are paired with the gene for a restriction enzyme. Decrease in a certain epigenetic methylation may lead to chromosome cleavage by the partner restriction enzyme, leading to eventual cell death. Thus, the pairing of a DNA methyltransferase and a restriction enzyme forces an epigenetic state to be maintained within the genome. Although restriction enzymes were originally discovered for their ability to attack invading DNAs, it may be understood because such DNAs show deviation from this epigenetic status. DNAs with epigenetic methylation, by a methyltransferase linked or unlinked with a restriction enzyme, can also be the target of DNases, such as McrBC of Escherichia coli, which was discovered because of its methyl-specific restriction. McrBC responds to specific genome methylation systems by killing the host bacterial cell through chromosome cleavage. Evolutionary and genomic analysis of McrBC homologues revealed their mobility and wide distribution in prokaryotes similar to restriction–modification systems. These findings support the hypothesis that this family of methyl-specific DNases evolved as mobile elements competing with specific genome methylation systems through host killing. These restriction systems clearly demonstrate the presence of conflicts between epigenetic systems.

show abstract

Section: Mcrbc a Methyl-specific Dna Endonuclease (Type IV Restrictimentioning

confidence: 99%

Conflicts Targeting Epigenetic Systems and Their Resolution by Cell Death: Novel Concepts for Methyl-Specific and Other Restriction Systems

2010

View full text Add to dashboard Cite

show abstract

“…However, variations to this general theme exist (e.g., the type IV MrcBC system [53], which has no separate MTase and cleaves only modified DNA substrates, or the type IIM subgroup, which recognizes methylated DNA). The restriction enzymes fall into a wide variety of families and subtypes (72), and these all produce different DNA products depending upon the mechanism of DNA cleavage (94).…”

Section: Background Of R-m Systemsmentioning

confidence: 99%

EcoR124I: from Plasmid-Encoded Restriction-Modification System to Nanodevice

Youell

Firman

2008

Microbiol Mol Biol Rev

View full text Add to dashboard Cite

SUMMARY Plasmid R124 was first described in 1972 as being a new member of incompatibility group IncFIV, yet early physical investigations of plasmid DNA showed that this type of classification was more complex than first imagined. Throughout the history of the study of this plasmid, there have been many unexpected observations. Therefore, in this review, we describe the history of our understanding of this plasmid and the type I restriction-modification (R-M) system that it encodes, which will allow an opportunity to correct errors, or misunderstandings, that have arisen in the literature. We also describe the characterization of the R-M enzyme EcoR124I and describe the unusual properties of both type I R-M enzymes and EcoR124I in particular. As we approached the 21st century, we began to see the potential of the EcoR124I R-M enzyme as a useful molecular motor, and this leads to a description of recent work that has shown that the R-M enzyme can be used as a nanoactuator. Therefore, this is a history that takes us from a plasmid isolated from (presumably) an infected source to the potential use of the plasmid-encoded R-M enzyme in bionanotechnology.

show abstract

“…The efficient cleavage of m5 C-containing DNA requires two methylated 5Ј PuC sites spaced apart by ca. 40 to 80 nonspecific base pairs (38).Several groups have studied the mcrBC locus, and most agree that this restriction system possesses two genes (11, 35) producing three gene products (11,19,33,34 McrBC restriction has been reported to be GTP dependent, and the mcrB gene contains a motif similar to the consensus GTP binding site (11,38). ATP was reported to efficiently inhibit cleavage, although a more recent study (20) disputes this.…”

mentioning

confidence: 99%

“…Several groups have studied the mcrBC locus, and most agree that this restriction system possesses two genes (11,35) producing three gene products (11,19,33,34). The mcrB gene directs the synthesis of two proteins: McrB L (ca.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Evidence of participation of McrB(S) in McrBC restriction in Escherichia coli K-12

1997

View full text Add to dashboard Cite

In Escherichia coli K-12, the McrBC restriction system recognizes and restricts DNA that is methylated at specific sequences. Whereas with most restriction systems DNA modification affords protection from restriction, in E. coli K-12 the McrBC restriction system will restrict, via endonuclease cleavage, DNA methylated at 5-hydroxymethylcytosine ( hm5 C) (27, 31), N 4 -methylcytosine ( m4 C), and 5-methylcytosine ( m5 C) (26, 30) at specific sequences. The ability to restrict hm5 C-containing T-even phage DNA which lacks a conjugated glucose moiety (41) is referred to as Rgl restriction (for restricts glucoseless phage) and was the first type of DNA restriction characterized (22). The efficient cleavage of m5 C-containing DNA requires two methylated 5Ј PuC sites spaced apart by ca. 40 to 80 nonspecific base pairs (38).Several groups have studied the mcrBC locus, and most agree that this restriction system possesses two genes (11, 35) producing three gene products (11,19,33,34 McrBC restriction has been reported to be GTP dependent, and the mcrB gene contains a motif similar to the consensus GTP binding site (11,38). ATP was reported to efficiently inhibit cleavage, although a more recent study (20) disputes this. GTP analogs with nonhydrolyzable ␤-␥ linkages or monoor diphosphates do not promote the reaction, suggesting that a hydrolyzable phosphate bond is necessary (38).The mcrB gene alone is sufficient to restrict DNA methylated by M ⅐ MspI ( m CCGG) or M ⅐ SssI ( m CG) (10, 11, 15). Highly purified McrB L and McrC were used for in vitro restriction assays and were found to confer the same restriction specificity as extracts prepared from mcrBC ϩ cells (38). Using these purified proteins, it was deduced that McrB L and McrC, but not McrB S , were required for restriction in vitro. No activity was seen for McrB S alone even when DNA modified by M ⅐ MspI or M ⅐ SssI, which is known to be restricted by the presence of a functional mcrB gene alone, was used as the substrate. It has remained unclear to date what role, if any, McrB S plays in restriction.This report presents in vivo study data which provide evidence that the McrB S protein serves as a regulatory protein that may modulate the formation of active McrBC restriction complexes. Among the parameters measured was the induction of the SOS response when the McrB S protein was underproduced by using antisense RNA. MATERIALS AND METHODSBacteria, phages, and plasmids. The bacterial strains, bacteriophages, and plasmid constructs used in this study are listed in Table 1.McrB assay using methylated lambda () phage. A 3.4-kb EcoRI fragment containing the BsuRI methylase gene from Bacillus subtilis R was ligated into EcoRI-cut pBR322. The resulting plasmid was designated pM ⅐ BsuRI ⅐ 10 (17). The phage vir was used to infect E. coli DH5␣MCR (pM ⅐ BsuRI ⅐ 10), and the lysate containing M ⅐ BsuRI-methylated vir was collected and used to assay McrB restriction (29). Methylated vir was designated ⅐ K ⅐ BsuRI, and nonmethylated vir was designated ⅐ 0.

show abstract

Characterization of the mcrBC region of Escherichia coli K-12 wild-type and mutant strains

Cited by 28 publications

References 29 publications

Conflicts Targeting Epigenetic Systems and Their Resolution by Cell Death: Novel Concepts for Methyl-Specific and Other Restriction Systems

Conflicts Targeting Epigenetic Systems and Their Resolution by Cell Death: Novel Concepts for Methyl-Specific and Other Restriction Systems

EcoR124I: from Plasmid-Encoded Restriction-Modification System to Nanodevice

Evidence of participation of McrB(S) in McrBC restriction in Escherichia coli K-12

Contact Info

Product

Resources

About