A primer is a short nucleic acid sequence that provides a starting point for DNA synthesis. The synthesis of a primer is necessary because the enzymes that synthesize DNA, which are called DNA polymerases, can only attach new DNA nucleotides to an existing strand of nucleotides. ...

Does DNA polymerase require a primer does RNA polymerase require a primer?

RNA polymerase II, the enzyme that synthesizes mRNA from DNA, never requires a primer. ... The enzyme could synthesize DNA in the absence of a primer, initiating with a dNTP. Furthermore, the enzyme recognizes a specific DNA sequence on the template to initiate de novo DNA synthesis.

Does DNA polymerase bind to a primer?

Two molecules of DNA polymerase III bind to the primers on the leading and lagging strands and synthesize new DNA from the 3′ hydroxyls (Fig. 4.5). DNA polymerase cannot synthesize new DNA without a pre-existing 3′-OH. Thus, DNA replication requires an RNA primer to initiate strand formation.