simplify

produced by luclease (Fig. 34.4) (Note: 10phage 14 can covalently join blunt 14DNA Ugase) if enzymes out stroughis auron 0. Restriction fragments both strands at the same position. Restriction endonucleases cleave dsDNA into fragments of differ- ent sizes (restriction fragments) depending upon the size of the restriction site sequence. For example, an enzyme that recognizes a specific 4-bp sequence produces many cuts in the DNA mol- ecule, one every 4" bps. In contrast, an enzyme requiring a unique sequence of 6 bps makes fewer cuts (one every 4% bps) and, there fore, produces longer pieces of DNA. Hundreds of these enzymes, each having different cleavage specificities (varying in both nucleo tide sequences and length of recognition sites) are commercially available