Specificity of restriction endonucleases and methylases — a review (edition 2)

Keßler, Christoph; Höltke, Hans-Joachim

doi:10.1016/0378-1119(86)90245-3

Cited by 99 publications

(40 citation statements)

References 351 publications

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“…Restriction systems in Streptomyces spp. are common (1,6,8,17,26,35), but this report is the first description of a methyl-specific restriction system in Streptomyces spp. Some bacteria methylate DNA to produce N4-methylcytosine (5,9).…”

Section: Resultsmentioning

confidence: 89%

“…(1,6,8,17,26,35). Most restriction-modification systems are composed of a methylase and an endonuclease.…”

mentioning

confidence: 99%

“…The modification enzyme (methylase) modifies the host DNA at a specific sequence composed of four or more bases, and the restriction endonuclease cleaves unmodified foreign DNA at or near the specific sequence (for a review, see reference 17). More than 600 restriction endonucleases and 98 methylases are known (17). Three methyl-specific restriction systems have been described elsewhere (19,31,36).…”

mentioning

confidence: 99%

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Characterization of a unique methyl-specific restriction system in Streptomyces avermitilis

1988

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Streptomyces avermitilis contains a unique restriction system that restricts plasmid DNA containing N6-methyladenine or 5-methylcytosine. Shuttle vectors isolated from Escherichia coli RR1 or plasmids isolated from modification-proficient Streptomyces spp. cannot be directly introduced into S. avermitilis. This restriction barrier can be overcome by first transferring plasmids into Streptomyces lividans or a modification-deficient E. coli strain and then into S. avermitilis. The transformation frequency was reduced >1,000-fold when plasmid DNA was modified by dam or TaqI methylases to contain N6-methyladenine or by AluI, HhaI, or HphI methylases to contain 5-methylcytosine. Methyl-specific restriction appears to be common in Streptomyces spp., since either N6-methyladenine-specific or 5-methylcytosine-specific restriction was observed in seven of nine strains tested.Streptomyces avermitilis produces avermectins, commercially important macrolide secondary metabolites with potent anthelmintic activities (4). Avermectins are active against almost all arthropod ectoparasites (10) and are effective in controlling numerous agricultural pests (30). Procedures to study the biosynthesis of secondary metabolites by using cloning vectors and recombinant DNA techniques have been developed for several Streptomyces species (for examples, see references 16, 18, and 33). However, certain procedures can be performed only with Escherichia coli (i.e., the use of lambda vectors, cosmids, M13 sequencing vectors, transposon mutagenesis, and regulated expression vectors). To take advantage of the procedures available with E. coli, Streptomyces-E. coli shuttle vectors have been made (20,21,29,37,38). Cloning systems developed for S. avermitilis include vectors derived from phage TG1 (12) and plasmid pVE1 (24) and an efficient transformation procedure (23). Unfortunately, Streptomyces-E. coli shuttle vectors cannot be introduced directly into S. avermitilis because S. avermitilis restricts the entry of DNA isolated from E. coli. This restriction barrier could also pose a problem in any attempt to produce hybrid antibiotics in S. avermitilis (15).Restriction-modification systems are widespread in Streptomyces spp. (1,6,8,17,26,35). Most restriction-modification systems are composed of a methylase and an endonuclease. The modification enzyme (methylase) modifies the host DNA at a specific sequence composed of four or more bases, and the restriction endonuclease cleaves unmodified foreign DNA at or near the specific sequence (for a review, see reference 17). More than 600 restriction endonucleases and 98 methylases are known (17). Three methyl-specific restriction systems have been described elsewhere (19,31,36). In strains with methyl-specific restriction systems, foreign methyl-modified DNA is restricted and the host does not modify DNA. Diplococcus pneumoniae restricts DNA containing N6-methyladenine at the sequence GATC (19).Two other strains restrict DNA containing 5-methylcytosine, but these strains show little or no sequence specifi...

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Section: Resultsmentioning

confidence: 89%

“…(1,6,8,17,26,35). Most restriction-modification systems are composed of a methylase and an endonuclease.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

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Characterization of a unique methyl-specific restriction system in Streptomyces avermitilis

1988

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“…Because the results of genetic studies on both cryptic and programmable forms of the element indicate that the phase setting is both heritable and reversible, we examined the accessibility of each element form to digestion with restriction enzymes that cannot cut C-methylated cleavage sites (Kessler and Holtke 1986). The general design of the experiments is illustrated by the 50.5…”

Section: The Spm Element Is Methylated Extensively But the A Gene Ismentioning

confidence: 99%

Molecular mechanisms in the developmental regulation of the maize Suppressor-mutator transposable element.

Banks¹,

Masson²,

Fedoroff³

1988

Genes Dev.

199

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The maize Suppressor-mutator (Spm) element can exist in one of three heritable forms: (1) a stably active form, (2) a stably inactive form, termed cryptic, and (3) a labile form, here termed programmable, in which the element exhibits one of a variety of heritable developmental programs of expression. Active elements are transcribed and are hypomethylated at sites upstream of the transcription start site, whereas inactive elements are transcriptionally silent and largely methylated at the upstream sites. Active (both stable and programmable), inactive programmable, and cryptic elements are unmethylated, partially methylated, and fully methylated, respectively, at sites within an 0.35-kb 80% G + C region just downstream from the transcription start site. An active Spin element in a genome with a cryptic element promotes its partial demethylation but not its transcriptional activation. In contrast, a trans-acting Spin promotes extensive demethylation and transcriptional activation of an inactive programmable element, as well as its heritable reactivation. These observations define the molecular components of the Spin element's developmental regulatory mechanism. We discuss their general relevance to the developmental regulation of gene expression.[ 1957, 1958, 1959, 1965aPeterson 1966;Fowler and Peterson 1978). These include the cryptic form, in which the element is genetically silent. Both McClintock and Peterson also identified elements that were capable of undergoing reversible transitions between the active and inactive phases in a characteristic and heritable pattern during development (McClintock 1957(McClintock , 1958(McClintock , 1962(McClintock , 1965a(McClintock , b, 1971Peterson 1966;Fowler and Peterson 1978). We showed recently that the genetic mechanism responsible for the developmental control of Spin expression has two components, which we designated the phase setting and the phase program (Fedoroff and Banks 1988). The phase setting determines whether the element is genetically active or inactive. The phase program determines the heritability of the phase setting, as well as when, where, and how frequently it will be reversed during plant development. The underlying genetic mechanism is heritable, reversible, and capable of promoting the incremental transition of the element from a stably active to a stably inactive (cryptic) form, implying the involvement of multiple epigenetic events (Fedoroff and Banks 1988). In view of the accumulating evidence that the inactivation of gene expression, in general (for reviews, see Razin et al. 1984;Adams and Burdon 1985;Holliday 1987;Cedar 1988), and maize transposable elements, in particular Bennetzen 1985;Chandler and Walbot 1986;Schwartz and Dennis 1986;Chomet et al. 1987; Fedoroff et al. 1988a, b)

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“…Although there are no reports of restriction endonucleases produced by X . c. campestris many other members of the genus are known to produce these enzymes (Kessler & Holtke, 1986). We therefore introduced pKT230 into X .…”

Section: Results a N D Discussionmentioning

confidence: 99%

Transformation of Xanthomonas campestris pathovar campestris with Plasmid DNA

Atkins

Barber²,

Daniels³

1987

Microbiology

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Procedures for the introduction of plasmid DNA into Gram-negative bacteria have been adapted and optimized to permit transformation of the plant pathogen Xanthomonas campestris pathovar campestris with the cloning vector pKT230 and other broad-host-range plasmids. The technique involves CaC1,-induced competence and heat shock and is similar to that routinely used for Escherichia coli. Wild-type X . c. campestris strains appear to restrict incoming unmodified DNA, so that plasmid DNA for transformation must be prepared from X . c. campestris (into which it has previously been introduced by conjugation). To overcome this disadvantage a restriction-deficient mutant has been isolated.

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Specificity of restriction endonucleases and methylases — a review (edition 2)

Cited by 99 publications

References 351 publications

Characterization of a unique methyl-specific restriction system in Streptomyces avermitilis

Characterization of a unique methyl-specific restriction system in Streptomyces avermitilis

Molecular mechanisms in the developmental regulation of the maize Suppressor-mutator transposable element.

Transformation of Xanthomonas campestris pathovar campestris with Plasmid DNA

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