Cleavage of DNA

Restriction enzymes (Section 28.14) Enzymes that catalyze the cleavage of DNA at specihc sites. 

Chang, A.Y. and P.B. Dervan. Strand selective cleavage of DNA by diastereo-mers of hairpin polyamide-seco-CBl conjugates. /. Am. Chem. Soc. 2000, 122, 4856-4864. 

Kndr, G. (2000) Molecular design of cationic sensitizers carrying redox active intercalator substituents Towards recognition and photocatalytic cleavage of DNA. Journal of Information Recording, 25, 111. 

Complexes such as [Ni(16)] are known to stoichiometrically interact with 02 to give 1 1 adducts and subsequently the autoxidized Ni111 species (compare Section 6.3.4.10.2(v)). 5 Such systems have been tested for the NiIII-catalyzed cleavage of DNA (see Section 6.3.4.10.2(v)). It has been suggested that Ni11 macrocycle complexes with rather low Nin/Nim reduction potentials can be active inhibitors of aldehyde autoxidation.156... 

The oxidizing power of the catalytic sulfite ion/02 systems was utilized in oxidative cleavage of DNA (118-121), in an analytical application for the determination of sulfur dioxide in air (122) and in developing a luminescent probe for measuring oxygen uptake (123). 

Restriction enzymes, sequence-dependent cleavage of DNA by, 12 497—498 Restriction fragment linked polymorphism (RFLP), 12 500 procedure, 12 103-104 Restriction sites, as genetic markers, 12 500... 

This activity is intended to be performed in conjunction with Experiment 66. Restriction endonucleases, or restriction enzymes, cleave DNA at specific base sequences, fragmenting the DNA into smaller pieces. The two strands of a DNA double helix are cleaved at different places, resulting in uneven fragments called sticky ends. Cleavage of DNA by restriction enzymes is a required first step in various types of DNA analysis, including DNA fingerprinting and recombinant DNA technology. 

Figure 20.35 Mechanisms by which external or internal stress leads to cell damage resulting in apoptosis. The stress leads to activation of initiator proteolytic enzymes (caspases) that initiate activation of effector caspases. These enzymes cause proteolytic damage to the cytoskeleton, plasma membrane and DNA. The activation of DNAases in the nucleus results in cleavage of DNA chains between histones that produces a specific pattern of DNA damage which, upon electrophoresis, gives a specific pattern of DNA fragments. The major endproduct of apoptosis are the apoptolic bodies which are removed by the phagocytes.

Rep-mediated site-specific cleavage of DNA, ATPase activity and transcriptional repression. EMBO J. 16, 5943-5954. 

Enzymes catalyzing cleavage of DNA, including endo-deoxyribonucleases that generate 5 -phosphomono-esters [EC 3.1.21.x], endodeoxyribonucleases that produce products other than 5 -phosphomonoesters [EC 3.1.22.x], site-specific endodeoxyribonucleases acting on altered bases [EC 3.1.25.x], and exodeoxyribonucleases producing 5 -phosphomonoesters [EC 3.1.11.x]. A few examples are ... 

Deoxyribonuclease I [EC 3.1.21.1], also known as pancreatic DNase and thymonuclease, catalyzes the endonucleolytic cleavage of DNA, preferring dsDNA, to a 5 -phosphodinucleotide and 5 -phosphooligonucleotide end products. 

Type II site-specific deoxyribonuclease [EC 3.1.21.4], also referred to as type II restriction enzyme, catalyzes the endonucleolytic cleavage of DNA to give specific, double-stranded fragments with terminal 5 -phosphates. Magnesium ions are required as cofactors. 

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