Modified Tn5 Transposases for Uniform DNA Fragmentation
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Solution Overview
Problem
Existing transposase enzymes exhibit poor insertion sequence bias and DNA input tolerance, leading to non-uniform DNA fragment sizes and sequencing inefficiencies in nucleic acid analysis methods.
Innovation Solution
Modified Tn5 transposases with specific mutations at positions such as Asp248, Glu54, and Leu372, along with fusion proteins like Maltose Binding Protein (MBP) or Elongation Factor Ts (Tsf), enhance insertion sequence bias and DNA input tolerance, allowing for uniform DNA fragmentation and tagging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wild type Tn5 transposase is used, then transposition activity is achieved, but insertion sequence bias is poor and DNA fragment sizes are non-uniform
Solution Approach 1:
The patent applies parameter changes by modifying specific amino acid residues in the Tn5 transposase sequence (positions 54, 56, 248, and 372) to alter the enzyme's DNA binding and cleavage properties. These sequence parameter modifications result in improved insertion bias and more uniform DNA fragment sizes compared to wild type transposase.
2Adaptability or versatility
If standard transposase is used, then basic fragmentation and tagging is achieved, but DNA input tolerance is limited
Solution Approach 1:
The patent modifies the transposase amino acid sequence parameters (positions 54, 56, 248, 372) to enhance the enzyme's ability to tolerate varying DNA input amounts. This allows reliable fragmentation and tagging across a broader range of DNA concentrations, improving adaptability to different sample conditions.
3Productivity
If wild type Tn5 transposase is used, then transposition function is maintained, but sample preparation efficiency is reduced due to bias and non-uniformity
Solution Approach 1:
By changing the amino acid sequence parameters of Tn5 transposase at specific positions, the patent achieves both improved insertion uniformity and enhanced sample preparation efficiency. The modified transposase generates more uniform DNA fragments with better representation, reducing the need for additional purification and normalization steps.
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 modified transposases provide improved insertion bias and DNA input tolerance, resulting in faster, more flexible, and efficient sample preparation for nucleic acid sequencing, enhancing coverage uniformity and reducing dropout regions.
Implementation Method 1
Transposase enzymes are useful in in vitro transposition systems. They allow for massive-scale fragmentation and tagging of genomic DNA
Data Source
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AI summary
Presented herein are transposase enzymes and reaction conditions for improved fragmentation and tagging of nucleic acid samples, in particular altered transposases and reaction conditions which exhibit improved insertion sequence bias, as well as methods and kits using the same.