Phi29 DNA Polymerase Mutagenesis for Stability and Sequencing Activity
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Solution Overview
Problem
The stability and enzyme activity of wild-type Phi29 DNA polymerase and commercial Phi29 DNA polymerase are inadequate for use in sequencing kits, leading to poor sequencing quality due to low reaction rates and short shelf life.
Innovation Solution
Site-directed mutagenesis and DNA shuffling are employed to create recombinant Phi29 DNA polymerases with specific amino acid substitutions at targeted positions, resulting in proteins with enhanced stability and enzyme activity, such as recombinant Phi29 DNA polymerases with T213K/L416A/V509E, M97T/Y224K/E515S, and R96S/L123P/Y224K/L416A/E515S mutations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wild-type Phi29 DNA polymerase is used, then the enzyme can perform basic DNA polymerization, but the stability is poor (less than one year) and reaction rate is low
Solution Approach 1:
The patent applies parameter changes by performing site-directed mutagenesis at specific amino acid positions (17, 96, 97, 99, 123, 140, 148, 158, 159, 171, 203, 204, 213, 217, 224, 250, 270, 309, 310, 320, 344, 345, 347, 369, 402, 416, 509, 515, 524) to optimize the enzyme's amino acid sequence. This changes the molecular parameters of the polymerase to achieve both improved stability and enhanced reaction rate, resolving the contradiction between reliability and productivity.
2Reliability
If wild-type Phi29 DNA polymerase is used, then the enzyme structure is simple, but the stability is insufficient for kit application
Solution Approach 1:
The patent applies local quality by performing site-directed mutagenesis at specific localized positions within the enzyme structure rather than global modification. By targeting specific amino acid positions (such as 213, 416, 509 for the T213K/L416A/V509E mutant), the patent makes localized changes to the polymerase structure that improve stability without substantially increasing overall structural complexity, thus resolving the contradiction between reliability and device complexity.
3Productivity
If commercial Phi29 DNA polymerase is used, then it is available for purchase, but the enzyme activity is low leading to poor sequencing quality
Solution Approach 1:
The patent applies parameter changes by optimizing the amino acid sequence through site-directed mutagenesis at specific positions to enhance enzyme activity. The mutated polymerases (such as T213K/L416A/V509E, M97T/Y224K/E515S, R96S/L123P/Y224K/L416A/E515S) exhibit higher polymerization activity, which directly improves sequencing quality by enabling more efficient DNA synthesis and amplification, thus resolving the contradiction between productivity and manufacturing precision.
Data Source
AI summary
Provided are a stable Phi29 DNA polymerase having high enzyme activity, and an encoding gene and an application thereof. The Phi29 DNA polymerase is obtained by substituting amino acid residue at at least one among the following 29 positions: position 17, position 96, position 97, position 99, position 123, position 140, position 148, position 158, position 159, position 171, position 203, position 204, position 213, position 217, position 224, position 250, position 270, position 309, position 310, position 320, position 344, position 345, position 347, position 369, position 402, position 416, position 509, position 515 and position 524 of a DNA polymerase shown in SEQ ID NO: 2.