Abstract: An enzymatic method of making a polynucleotide is provided. The method includes combining a selected nucleotide triphosphate, one or more cations, a template-independent polymerase, and an associated processivity factor in an aqueous reaction medium including a target substrate comprising an initiator sequence and having a 3? terminal nucleotide attached to a single stranded portion, such that the template-independent polymerase and the associated processivity factor interact with the target substrate under conditions which covalently add one or more of the selected nucleotide triphosphate to the 3? terminal nucleotide. Also provided are mutant template-independent polymerases having a processivity factor attached thereto.