PathwayStep471 PathwayStep470 The polymerase component of DNA polymerase alpha:primase synthesizes a 20-nucleotide primer at the origin The primase component of DNA polymerase:primase synthesizes a 6-10 nucleotide RNA primer at the origin DNA replication initiation DNA polymerases are not capable of de novo DNA synthesis and require synthesis of a primer, usually by a DNA-dependent RNA polymerase (primase) to begin DNA synthesis. In eukaryotic cells, the primer is synthesized by DNA polymerase alpha:primase. First, the DNA primase portion of this complex synthesizes approximately 6-10 nucleotides of RNA primer and then the DNA polymerase portion synthesizes an additional 20 nucleotides of DNA (Frick & Richardson 2002; Wang et al 1984). GENE ONTOLOGYGO:0006270 Pubmed11395402 Pubmed6693436 Reactome Database ID Release 4368952 Reactome, http://www.reactome.org ReactomeREACT_2244