Would the lagging or leading strand be more affected by a mu

Would the lagging or leading strand be more affected by a mutation that prevents ligase from working? Explain your reasoning. AB T T T Arial 3 (12pt) Path: p Words:0

Solution

Lagging strand is affected more than leading strand by mutation that prevents ligase from working as replication of the DNA strand in the lagging strand is not continuous i.e. it occurs in pieces of small stretches called as Okasaki fragments. To join the pieces of newly replicated fragments a enzyme comes to play by ligating the strand through forming phosphodiester bond between the 3\'OH of one fragment and 5\' phosphate of the next Okasaki fragment. So if the ligase action is prevented or lacking it will affect the lagging strand.

The double stranded deoxyribonuclease (DNA) duplicates its own copy by the process called DNA replication in which with the double stranded DNA unwinds and with a guiding sequence on one strand deoxyribonucleotides are complementarily added i.e. for deoxyribonucleotide A complementary base pairing occurs with T, likewise A against T, C against G and vice versa. Deoxyribonucleotide is added to the 3\' end of primer DNA strand and Okasaki fragments are synthesized by adding complementary deoxyribonucleotide (polymerization) by the DNA polymerase enzyme.

So the complementary strand to DNA sequence ATGTTTGACG is 3’ (Three prime)-TACAAACTGC-5’ by the rule discussed above.