When circular doublestranded DNA from the plasmid pCEL1 is d

When circular double-stranded DNA from the plasmid pCEL1 is digested by various restriction endonucleases and combinations thereof, the following bands (with lengths given in kilobase pairs) are observed: EcoRI, 6.0; BamHI, 6.0; HindIII, 6.0; HaeII, 3.0, 2.0, and 1.0; EcoRI and HaeII, 2.0 and 1.0; EcoRI and HindIII, 3.5 and 2.5; EcoRI and BamHI, 4.5 and 1.5; BamHI and HindIII, 5.0 and 1.0; BamHI and HaeII, 3.0, 1.5, 1.0, and 0.5; and HindIII and HaeII, 3.0, 1.5, 1.0, and 0.5. Construct a restriction endonuclease enzyme site map with this information.

Solution

By seeing the sizes of the fragment, we can tell it’s a 6 kb fragment. compare the digest of BamHI and HindIII with BamHI and HaeII, here we can see the a 5 kb fragment with BamH1 and HindIII, but only 3 Kb fragment with BamH1 and HaeII, so first fragment will be 2 kb (5-3) and

Now it 2 kb—1.5kb----1.0kb-----0.5kb. Altogether we got 5 kb. Only 1kb is left, in the digest produced by BamHI and HindIII, the last fragment is 1.kb

If you keep everything in order

----2 kb—1.5kb----1.0kb-----0.5kb----1kb--- (Make this circular, you give complete restriction map)