Genetic Biology Questions. See attached file for full problem description.
1. To solve this restriction map, you have to make a few assumptions and see if it holds true. Notice that the 2.5 Kb fragment of the SmaI digest still exists in the double digest. In addition, the 3.5 Kb XbaI fragment exists in the double digest. Therefore, we know that these two fragments are at the ends. Armed with this information, all we need to do is try a few trial and error fragments for the remaining restriction sites to see how it all fits together. Here's the final map:
3.5 Kb --- XbaI --- 0.5 Kb --- SmaI --- 6.0 Kb --- XbaI --- 1.5 Kb --- SmaI --- 2.5 Kb
2a. Since the ATG is on the 3' side of the first mutation, that mutation wouldn't affect the amino acid sequence of the polypeptide. Exchanging one purine for another purine (or one pyrimdine for another pyrimidine) is a transition. Therefore, this is a transition. The codons are:
5' -- ATG CTG GGC ATT CAA CCG
The amino acid sequence would be: met-leu-gly-ile-gln-pro
2b. If we remove the T, we get a frameshift mutation that throws everything off 3' of the deletion. The sequence would be:
5' -- ATG CTG GGC ATC AAC ...
The amino acid ...