The primer is later removed by enzymes that have endonucleolytic activity such as Ribonuclease H ( RNAse H), flap endonucleases (FENs) and Dna2 helicase/nucleases. In eukaryotes, lagging strand synthesis is carried out by the DNA polymerase δ. Regarding the lagging strand, the result of this strand's discontinuous replication is the production of a series of short sections of DNA called Okazaki fragments.Įach Okazaki fragment is initiated near the replication fork at an RNA primer created by primase, and extended by DNA polymerase III. Because the original strands of DNA are antiparallel, and only one continuous new strand can be synthesised at the 3' end of the leading strand due to the intrinsic 5'-3' polarity of DNA polymerases, the other strand must grow discontinuously in the opposite direction.
Its antiparallel complement strand, the nascent lagging strand reads from 3' to 5'. In dealing with the synthesis of complementary DNA strands the nascent leading strand always reads 5' to 3'. These fragments are processed by the replication machinery to produce a continuous strand of DNA and hence a complete daughter DNA helix. When the lagging strand is being replicated on the original strand, the 5'-3' pattern must be used thus a small discontinuity occurs and an Okazaki Fragment forms. Better weighing performance in 6 easy steps
