The polymerase component of DNA polymerase alpha:primase synthesizes a 20-nucleotide primer at the origin

At the beginning of this reaction, 1 molecule of 'dTTP', 1 molecule of 'dGTP', 1 molecule of 'dATP', 1 molecule of 'RNA primer:origin duplex:DNA polymerase alpha:primase complex', and 1 molecule of 'dCTP' are present. At the end of this reaction, 1 molecule of 'RNA primer-DNA primer:origin duplex' is present.<br><br> This reaction takes place in the 'nucleus' and is mediated by the 'DNA-directed DNA polymerase activity' of 'DNA polymerase alpha:primase'.<br>

在此反应的初始阶段，存在1分子dTTP、1分子dGTP、1分子dATP、1分子RNA引物-起源双链-DNA聚合酶α-引物酶复合物以及1分子dCTP。在反应结束时，存在1分子RNA引物-DNA引物-起源双链。该反应发生在细胞核中，并由DNA聚合酶α-引物酶的DNA指导DNA聚合酶活性所介导。