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Ligation of nonmatching DNA molecule ends
C Cimmino1, F Santori, P Donini
1Dipartimento di Biologia Cellulare e dello Sviluppo, Università di Roma La Sapienza, Italy.
Plasmid
|July 1, 1995
Summary
T4 DNA ligase efficiently joins blunt DNA ends with nonmatching ends, including those with 2-nucleotide protrusions. This DNA ligation process trims protrusions and can be used in molecular cloning.
Area of Science:
- Molecular Biology
- Enzymology
- Biochemistry
Background:
- T4 DNA ligase is a key enzyme for joining DNA fragments.
- Understanding its ligation capabilities with non-standard DNA ends is crucial for molecular biology applications.
Purpose of the Study:
- To investigate the ability of T4 DNA ligase to ligate blunt DNA ends with ends possessing single-stranded protrusions.
- To characterize the efficiency and mechanism of such non-matching DNA ligations.
Main Methods:
- Digestion of plasmids (pBR322, pSP71) with restriction enzymes.
- Recircularization of digested plasmids and transformation of Escherichia coli.
- Sequencing of ligation junctions to analyze the ligation products.
Main Results:
- T4 DNA ligase successfully ligated blunt ends to ends with 2-nucleotide protrusions.
- Ligation efficiency was comparable to blunt-end ligations.
- Sequencing revealed trimming of protrusions and, in some cases, loss of additional nucleotides.
- Intermolecular ligation of non-matching ends was also demonstrated.
Conclusions:
- T4 DNA ligase exhibits versatility in ligating non-matching DNA ends.
- The enzyme trims protrusions during ligation, enabling novel cloning strategies.
- This capability expands the utility of T4 DNA ligase in molecular cloning.