Artificial restriction enzymes

Artificial Restriction Enzymes As Tools For Future Molecular Biology and Biotechnology... 

This chapter describes artificial enzymes that can hydrolyze DNA at the target-site with desired site-specificity [1], With these totally man-made tools (artificial restriction enzymes), even huge DNA can be cut at a predetermined position and used for the preparation of recombinant DNA. This manipulation is hardly accomplishable as long as only naturally occurring restriction enzymes are used. Hopefully, these tools will open the way to new molecular biology and biotechnology in which the DNA of higher animals and plants can be manipulated. 

The importance of artificial restriction enzymes has been well understood by many chemists, and several challenging attempts have been made already. Although many difficulties remain, elegant work by many people is paving the way. This chapter deals mainly with the recent work of our laboratory on site-selective DNA scission and its applications to biotechnology. 

Molecular Design of Artificial Restriction Enzymes (Covalent vs. Non-Covalent Strategy) 161... 

Covalent Strategy for the First-generation of Artificial Restriction Enzymes... 

Design of Artificial Restriction Enzymes for Double-stranded DNA Scission... 

Figure 7.11 Schematic representation for manipulation of double-stranded DNA using the present artificial restriction enzyme.

Non-covalent Strategy for the Second-generation of Artificial Restriction Enzymes 162... 

Cleaving Genes - Restriction Enzymes Restriction enzymes can cleave nucleic acids at specific sequences. Artificial restriction enzymes can be prepared by combining oligo(nucleic acids) and supramolecular catalytic sites. 

Before we consider an artificial restriction enzyme, we will briefly explain the mechanism by which ribonuclease A hydrolyzes RNA (Fig. 6.12). In the... 

In order to develop an artificial restriction enzyme that can cleave a desired sequence, an oligonucleotide tag needs to be attached to the catalysis site. The artificial enzyme shown in Fig. 6.15 has an oligonucleotide tag (the rectangle) connected to a metal-chelate-type catalysis site (the circle). The catalytic site was fixed to a particular site on the substrate upon base pairing between the artificial enzyme and the substrate. When the Lu-chelate site was connected to single-stranded DNA, and the DNA moiety was hybridized to RNA with the complementary sequence, the RNA was hydrolyzed at the desired site. If the DNA sequence in the artificial enzyme is designed appropriately, RNA can be cleaved at any site desired. 

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