Non-Covalent Interactions between dUTP C5-Substituents and DNA Polymerase Decrease PCR Efficiency.

Area of Science:

• Biochemistry
• Molecular Biology
• Computational Chemistry

Background:

• Deoxyribonucleoside triphosphates (dNTPs) are essential substrates for DNA polymerases.
• Modified dNTPs can exhibit altered properties, influencing polymerase activity and PCR outcomes.
• Understanding polymerase-dNTP interactions is crucial for developing novel molecular tools.

Purpose of the Study:

• To investigate the impact of modified dUTPs on PCR amplification efficiency across various DNA polymerases.
• To correlate experimental PCR data with molecular modeling predictions of polymerase-dNTP interactions.
• To identify key molecular features governing the activity of modified dNTPs in enzymatic DNA synthesis.

Main Methods:

• Utilized molecular modeling to study deoxyuridine triphosphates (dUTPs) with novel polymerase-specific properties.
• Performed PCR amplification experiments using modified dUTPs with a panel of DNA polymerases (Taq, Tth, Pfu, Vent, Deep Vent, Vent (exo-), Deep Vent (exo-)).
• Compared experimental PCR efficiency data with 3D structural modeling of KlenTaq polymerase-DNA-dNTP complexes.

Main Results:

• Modified dUTPs, functionalized with bulky or aromatic groups, were tested for PCR amplification efficiency.
• A decrease in PCR efficiency was observed with increasing numbers of non-covalent bonds between dUTP substituents and DNA polymerase.
• Approximately a 15% decrease in PCR efficiency per additional non-covalent bond was quantified.
• The findings were generalized to DNA polymerases of families A and B.

Conclusions:

• The number of non-covalent bonds between dNTP substituents and DNA polymerase is a critical determinant of PCR efficiency.
• This interaction parameter can be modulated to regulate DNA polymerase activity.
• Molecular modeling provides a valuable approach for predicting and understanding the behavior of modified dNTPs in enzymatic reactions.