Okazaki fragments

1. Ahmed Ghobashi Okazaki fragments

2. Okazaki fragments are short, newly synthesized DNA fragments that are formed on the lagging template strand during DNA replication . Okazaki fragments are between 1000 and 2000 nucleotides long in Escherichia coli and are approximately 150 nucleotides long in eukaryotes . They are separated by ~ 10 -nucleotide RNA primers and are unligated until RNA primers are removed, followed by enzyme ligase connecting the two Okazaki fragments into one continuous newly synthesized complementary strand.

3. On the leading strand DNA replication proceeds continuously along the DNA molecule, but on the lagging strand the new DNA is made in fragments, which are later joined together by a DNA ligase enzyme . This is because the enzymes that synthesise the new DNA can only work in one direction along the parent DNA molecule (DNA is synthesized from 5' to 3).