Which Restriction enzyme are studied in Recombinant DNA Technology?

Answer 1

It's not the restriction enzymes that are studied, its the DNA. The enzyme cuts or "restricts" the DNA strand at a known sequence of nucleotides. Different enzyme, different sequence.

For a Biomanufacturing application, where we want to insert foreign DNA, the gene of interest is cut and spliced with a restriction enzyme into a recombinant plasmid, transformed into a bacteria, and sent merrily on it's way to make Insulin, or whatever.

With an unknown piece of DNA (a functional gene that makes a protein of interest or is being studied), the plasmid has "restriction sites" or nucleotide sequences, for several restriction enzymes, all of which I have mapped out. The unknown piece of DNA is cut at each end by a single restriction enzyme and inserted into the plasmid, which gives me some landmarks. I insert the plasmid into a bacteria, grow a culture so the bacteria makes many millions of copies of the plasmid, extract the plasmid, and run an experiment called a restriction digest.

The restriction digests are a series of reaction with single enzyme and combinations of two and three enzymes, all cutting the plasmid at different nucleotide sequences. Then I run an agarose gel electrophoresis, which separates all the different pieces of DNA by size, and do an analysis called a Restriction Map. This counts the DNA fragments and their sizes, which enzyme and combination of enzymes produced which sizes and how many fragments, which enzyme cuts where, which cuts were definitely in the known part of the plasmid, which were probably in the unknown DNA, adding up nucleotide sequence numbers to make sure different mapping guesses agree, etcetera, etcetera, and so forth. Until at last, a map of the size and restriction sites of the unknown DNA insert into the known plasmid vector is deduced. This used to be done by hand, but there are computer programs that do it now.

This is Research, the Technology is down the line a few steps when the gene has been characterized, the protein produced has been characterized, the trials are done, and the restriction enzyme to insert the gene into the bacteria for Bioman has been established