Question

How does restriction endonuclease act on a DNA molecule?

Answer 1

A restriction enzyme or restriction endonuclease is an enzyme that cleaves DNA into fragments at or near specific recognition sites within the molecule known as restriction sites.[1][2][3] Restrictions enzymes are one class of the broader endonuclease group of enzymes. Restriction enzymes are commonly classified into five types, which differ in their structure and whether they cut their DNA substrate at their recognition site, or if the recognition and cleavage sites are separate from one another. To cut DNA, all restriction enzymes make two incisions, once through each sugar-phosphate backbone (i.e. each strand) of the DNA double helix.

Answer 2

When a restriction endonucleaserecognizes a sequence, it snips through the DNA molecule by catalyzing the hydrolysis (splitting of a chemical bond by addition of a watermolecule) of the bond between adjacent nucleotides. ... Type IVrestriction enzymes cleave only methylated DNA and show weak sequence specificity

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