In-house Extraction and Purification of Pfu-Sso7d, a High-processivity DNA Polymerase

The polymerase chain reaction (PCR) is an extensively used technique to quickly and accurately make many copies of a specific segment of DNA. In addition to naturally existing DNA polymerases, PCR utilizes a range of genetically modified recombinant DNA polymerases, each characterized by varying levels of processivity and fidelity. Pfu-Sso7d, a fusion DNA polymerase, is obtained by the fusion of Sso7d, a small DNA-binding protein, with Pfu DNA polymerase. Pfu-Sso7d is known for its high processivity, efficiency, and fidelity but is sold at a sumptuously high price under various trade names and commercial variants. We recently reported a quick and easy purification protocol that utilizes ethanol or acetone to precipitate Pfu-Sso7d from heat-cleared lysates. We also optimized a PCR buffer solution that outperforms commercial buffers when used with Pfu-Sso7d. Here, we provide a step-by-step guide on how to purify recombinant Pfu-Sso7d. This purification protocol and the buffer system will offer researchers cost-efficient access to fusion polymerase. Key features • We detail a precipitation-based protocol utilizing ethanol and acetone for purifying Pfu-Sso7d. • Despite ethanol and acetone displaying effective precipitation efficiency, acetone is preferred for its superior performance. • Furthermore, we present a PCR buffer that outperforms commercially available PCR buffers. • The Pfu-Sso7d purified in-house and the described PCR buffer exhibit excellent performance in PCR applications.

Quick and easy method for extraction and purification of Pfu-Sso7d, a high processivity DNA polymerase

The polymerase chain reaction is an extensively used technique with numerous applications in the field of biological sciences. In addition to naturally occurring DNA polymerases with varying processivity and fidelity, genetically engineered recombinant DNA polymerases are also used in PCR. The Pfu-Sso7d, a fusion DNA polymerase, is obtained by the fusion of Sso7d, a small DNA binding protein, to the polymerase domain of the Pfu DNA polymerase. Pfu-Sso7d is known for its high processivity, efficiency, and fidelity. Expensive commercial variants of Pfu-Sso7d are sold under various trade names. Here, we report a quick, cost and time-efficient purification protocol and an optimized buffer system for Pfu-Sso7d. We evaluated precipitation efficiencies of varying concentrations of ethanol and acetone and compared the activities of the precipitated enzyme. Although both the solvents efficiently precipitated Pfu-Sso7d, acetone showed better precipitation efficiency. Purified Pfu-Sso7d showed excellent activities in the PCR of templates with varying lengths and GC contents. We also report a buffer system that works with Pfu-Sso7d as efficiently as commercially available buffers. This quick and efficient purification scheme and buffer system will provide researchers cost-efficient access to fusion polymerases.