Mutant Reverse Transcriptase for 3′-Modified Nucleotide Sequencing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Next-generation sequencing techniques require improvements in sensitivity, accuracy, scalability, and cost efficiency, particularly in methods like sequencing-by-synthesis where incorporating modified nucleotides is challenging.
Innovation Solution
Development of mutant nucleic acid polymerases, specifically reverse transcriptases, with mutations at positions K152, D153, A154, F155, F156, and Q190, which enhance the incorporation of 3′ modified nucleotides such as 3′ methylazido-dUTP, increasing incorporation rates and reducing Km values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wild-type reverse transcriptase is used for sequencing-by-synthesis, then the method is simpler to implement, but the incorporation efficiency of 3′ modified nucleotides is insufficient
Solution Approach 1:
The patent applies parameter changes by mutating specific amino acid residues in the reverse transcriptase enzyme at positions K152, D153, A154, F155, F156, and Q190. These parameter changes in the enzyme's primary structure result in altered catalytic properties, specifically increasing the incorporation efficiency of 3′ modified nucleotides by up to 50% compared to wild-type enzyme.
2Productivity
If mutant reverse transcriptase with multiple mutations is used, then the incorporation rate of 3′ modified nucleotides increases significantly, but the enzyme engineering and optimization process becomes more complex
Solution Approach 1:
The patent applies local quality by focusing mutations on specific critical residues (K152, D153, A154, F155, F156, Q190) within the enzyme's active site rather than random mutagenesis. This targeted approach at local positions achieves high incorporation rates while reducing the overall complexity of enzyme development compared to comprehensive mutagenesis strategies.
3Measurement precision
If standard polymerase is used, then the sequencing method is more cost-effective, but the sensitivity and accuracy of detecting modified nucleotides is reduced
Solution Approach 1:
The patent applies mechanics substitution by replacing the standard polymerase enzyme with an engineered reverse transcriptase that has enhanced catalytic properties. This substitution of the biological catalyst achieves both higher incorporation efficiency of modified nucleotides and improved measurement precision in sequencing applications, overcoming the limitations of using standard polymerases.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The mutant polymerases exhibit up to 50% higher incorporation of 3′ methylazido-dUTP and improved kcat/Km values, enhancing the sensitivity and accuracy of nucleic acid sequencing processes.
Implementation Method 1
mutant nucleic acid polymerases, specifically reverse transcriptases, with mutations at positions K152, D153, A154, F155, F156, and Q190, which enhance the incorporation of 3′ modified nucleotides such as 3′ methylazido-dUTP
Data Source
AI summary
Provided herein are compositions and methods for the incorporation of unnatural nucleotides using mutant polymerases, such as reverse transcriptases. Further provided herein are methods of detection and sequencing of polynucleotide sequences. In some aspects, the compositions and methods are used enhance the efficiency and speed of detecting nucleotide bases. The methods and compositions described herein may further reduce time, cost, or scale of devices for next generation sequencing platforms.