Recombinant DNA Polymerases Tuned for Single-Molecule Sequencing
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Solution Overview
Problem
Existing DNA polymerases lack desirable properties for applications such as single-molecule sequencing, genotyping, and real-time monitoring of amplification, requiring improved catalytic efficiency and specificity for nucleotide analog incorporation.
Innovation Solution
Development of recombinant DNA polymerases with specific mutations, such as E375Y and K512Y, and optional additional mutations at positions like L253, A484, V250, E239, Y224, Y148, E508, and T368, enhancing properties like exonuclease deficiency, closed conformation stabilization, and altered interactions with nucleotides for improved performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wild-type DNA polymerases are used, then the polymerase can perform standard DNA replication, but the polymerase lacks desirable properties for single-molecule sequencing and real-time monitoring applications
Solution Approach 1:
The patent applies parameter changes by introducing specific amino acid mutations (E375Y, K512Y, and optional mutations at positions L253, A484, V250, E239, Y224, Y148, E508, and T368) to modify the polymerase properties. These mutations alter the polymerase's kinetic parameters, thermostability, and conformational dynamics to achieve optimal performance for single-molecule sequencing applications while maintaining DNA replication functionality
2Manufacturing precision
If DNA polymerase mutations are introduced to enhance sequencing performance, then readlength and accuracy improve, but the polymerase structure and kinetics are altered
Solution Approach 1:
The patent applies local quality by introducing mutations at specific localized positions (E375, K512, and optional positions L253, A484, V250, E239, Y224, Y148, E508, T368) within the polymerase structure. Each mutation is strategically placed to affect specific functional properties (nucleotide binding, catalytic activity, conformational stability) without disrupting the overall polymerase structure, thereby improving readlength while maintaining structural integrity
3Measurement precision
If polymerase mutations are introduced to improve nucleotide analog incorporation, then sequencing accuracy improves, but catalytic efficiency may be affected
Solution Approach 1:
The patent optimizes the balance between accuracy and catalytic efficiency by carefully selecting mutation combinations. The E375Y and K512Y mutations, along with optional mutations at specific positions, are designed to enhance nucleotide analog incorporation fidelity while maintaining acceptable catalytic rates. The optional mutations provide fine-tuning capability to adjust the accuracy-efficiency trade-off based on specific application requirements
Data Source
AI summary
Provided are compositions comprising recombinant DNA polymerases that include amino acid substitutions, insertions, deletions, and/or exogenous features that confer modified properties upon the polymerase for enhanced single molecule sequencing. Such properties can include enhanced metal ion coordination, reduced exonuclease activity, reduced reaction rates at one or more steps of the polymerase kinetic cycle, decreased branching fraction, altered cofactor selectivity, increased yield, increased thermostability, increased accuracy, increased speed, increased readlength, and the like. Also provided are nucleic acids which encode the polymerases with the aforementioned phenotypes, as well as methods of using such polymerases to make a DNA or to sequence a DNA template.