We have talked about the SV40 T-antigen (LTA) in class. One function we did not discuss is the fact that it also involved with SV40 replication. If you add the PSF-CMV-UB-HYGRO-SV40 ORI SBFI plasmid, which contains the SV40 ori together with the LTA, ATP and SSBP (single stranded binding proteins) into a tube and look under a TEM microscope a paritally open DNA strucutre is seen. The LTA is bound on either end of the fork. You are intrigued by this, so you make a small deletion in the viral ori and found no unwound structures. Using this info answer the following questions

a. You now know the LTA has the ability to bind the SV40 DNA. What other activity would the LTA need to function in this manner and how would this function be used in initiating DNA replication?

b. You are not a rich lab, so you don't have too much beam time at the TEM lab. But you want to ensure that DNA repication from the DV40 ori is bi-directional, using restriction endonucleases (You do not need to specificy a specific restriction endonuclease) how would you show that DNA unwinding from the viral ori occurs mon-directional or bi-directional as the for opens up?