Mutant Lambda Integrase Enhances Recombination Specificity
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Solution Overview
Problem
Current lambda integrases face challenges in achieving efficient and specific site-specific recombination in human cells, often resulting in non-cognate site recombination due to the absence of an attB site in the human genome, making controlled and reproducible genetic engineering difficult.
Innovation Solution
Development of lambda integrase mutants with specific amino acid mutations, such as I43F, E319G, and D336V, which enhance recombination efficiency and specificity by optimizing the recognition of non-cognate sites like attH and attH4X, allowing for improved integration of nucleic acids into target sites.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wild-type lambda integrase is used for site-specific recombination in human cells, then recombination can occur, but specificity is reduced leading to non-cognate site recombination
Solution Approach 1:
The patent applies parameter changes by introducing specific amino acid substitutions (I43F, E319G, D336V) in the integrase protein sequence to modify its DNA binding properties. These parameter changes in the protein structure enable the integrase to distinguish between cognate and non-cognate sites more effectively, thereby improving recombination specificity in human cells.
2Manufacturing precision
If mutant integrases are developed to improve specificity, then recombination precision increases, but enzyme complexity increases
Solution Approach 1:
The patent applies local quality by introducing mutations at specific localized positions (I43, E319, D336) within the integrase protein rather than throughout the entire sequence. This localized modification approach achieves improved recombination precision while minimizing overall enzyme complexity, as only three specific residues are altered to confer enhanced specificity.
3Productivity
If standard lambda integrase is used, then the system is simple to operate, but recombination efficiency is insufficient for controlled genetic engineering
Solution Approach 1:
The patent applies parameter changes by modifying key amino acid parameters in the integrase sequence to enhance its catalytic efficiency and specificity. The I43F, E319G, and D336V mutations optimize the enzyme's interaction with DNA substrates, thereby improving recombination efficiency while maintaining relative operational simplicity through the use of a single engineered enzyme variant.
Data Source
AI summary
The present invention refers to lambda integrases comprising at least one amino acid mutation at positions 43, 319 and 336 of the lambda integrase as set forth in SEQ ID NO: 1. The invention further refers to nucleic acid molecules comprising the nucleotide sequence encoding the mutant lambda integrase and to host cells containing these nucleic acid molecules. The invention also refers to methods of recombining a nucleic acid of interest into a target nucleic acid in the presence of the mutant lambda integrase and sequence specific recombination kits.