dna polymerase activity
1 A 5'â3' (forward) RNA-Dependent DNA polymerase activity. 2  Pol I operates on RNA templates with considerably lower efficiency (0.1â0.4%) than it does DNA templates, and this activity is probably of only limited biological significance. A 3'â5' (reverse) exonuclease activity that mediates proofreading. 2  A 5'â3' (forward) exonuclease activity mediating nick translation during DNA repair. 3  A 5'â3' (forward) RNA-Dependent DNA polymerase activity.