Engineered Reverse Transcriptase for Specific cDNA Synthesis
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Solution Overview
Problem
Current methods for reverse transcription in gene expression analysis suffer from non-specific cDNA synthesis, leading to biased sequence representations and interference in downstream analyses like real-time PCR.
Innovation Solution
Development of a non-naturally occurring enzyme comprising domains derived from R2 retrotransposons, which is used to synthesize cDNA with improved specificity and processivity, reducing non-specific priming events.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional reverse transcriptase enzymes are used for cDNA synthesis, then the process can be performed with standard equipment and procedures, but non-specific priming events occur leading to reduced specificity and interference in downstream analyses
Solution Approach 1:
The patent modifies the reverse transcriptase enzyme by changing parameters of its active site and structural domains. Specifically, mutations are introduced in the fingers, palm, and thumb domains to alter the enzyme's binding specificity and reduce non-specific priming, thereby improving cDNA synthesis reliability without compromising the ability to perform the reaction under standard conditions
2Adaptability or versatility
If reverse transcriptase allows formation of both perfectly matched and mismatched DNA/RNA hybrids at room temperature, then the enzyme can initiate DNA synthesis from various primer sequences, but large amounts of non-specific cDNA products are produced interfering with downstream analyses
Solution Approach 1:
The patent applies local quality changes by introducing mutations in specific local regions of the reverse transcriptase enzyme (fingers, palm, and thumb domains) while maintaining the overall enzyme function. These localized changes enhance the enzyme's ability to distinguish between perfectly matched and mismatched primer-template hybrids, allowing specific primer binding while preventing non-specific cDNA product formation
3Ease of manufacture
If non-specific reverse transcriptase activity is present, then cDNA synthesis can proceed with standard enzymes, but false signals are generated in real-time PCR analyses complicating the interpretation of results
Solution Approach 1:
The patent converts the potentially harmful non-specific priming activity of reverse transcriptase into a beneficial specific priming mechanism. By engineering the enzyme with mutations in the fingers, palm, and thumb domains, the enzyme is modified to preferentially bind perfectly matched primer-template hybrids, transforming the source of false signals into a source of high-specificity cDNA synthesis that improves real-time PCR measurement accuracy
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 use of this non-naturally occurring enzyme enhances the specificity of cDNA synthesis, reducing interference in subsequent analyses and providing more accurate representations of mRNA sequences.
Implementation Method 1
enzymes with reverse transcriptase activity can be utilized to produce cDNA copies of the RNA sequence, utilizing the RNA/DNA primer as a template
Implementation Method 2
oligonucleotide sequences are annealed to the isolated mRNA molecules and enzymes with reverse transcriptase activity can be utilized to produce cDNA copies
Data Source
AI summary
The present disclosure provides methods and systems for amplifying and analyzing nucleic acid samples. The present disclosure provides methods for preparing cDNA and/or DNA molecules and cDNA and/or DNA libraries using modified reverse transcriptases.