Definition

1. Noun:
   • A type of enzyme: A restriction nuclease is a protein that acts as a catalyst to cut DNA molecules at very specific, recognized sequences of nucleotides.
   • Biological function and source: These enzymes are naturally produced by bacteria as a defense mechanism to cut and disable the DNA of invading viruses.
   • Biotechnology tool: In laboratory science, restriction nucleases are essential tools for cutting DNA at precise locations, enabling gene splicing, analysis, and recombinant DNA technology.

Usage Examples

• Noun:
  • The scientist used a restriction nuclease to cut the plasmid DNA at the target site.
  • Different restriction nucleases recognize and cut different DNA sequences.
  • The discovery of restriction nucleases was a breakthrough for molecular biology.

Advanced Usage

• "Restriction nuclease digestion": The process of using the enzyme to cut DNA into fragments.

  • The first step in cloning is restriction nuclease digestion of the DNA samples.

• "Restriction nuclease site": The specific short DNA sequence recognized and cut by the enzyme.

  • The gene of interest was inserted into a plasmid at a unique restriction nuclease site.

Variants and Related Words

• Restriction enzyme (n): The most common synonym for restriction nuclease.

  • EcoRI is a well-known restriction enzyme.

• Endonuclease (n): A broader category of enzymes that cut within a DNA strand; all restriction nucleases are endonucleases.

  • Unlike exonucleases, endonucleases like restriction nucleases cut internally.

• Restriction fragment (n): A piece of DNA resulting from being cut by a restriction nuclease.

  • The DNA was separated into restriction fragments by gel electrophoresis.

Synonyms

• Restriction enzyme: A functionally identical term more frequently used in common laboratory parlance.
• Molecular scissors: A descriptive, informal term highlighting the cutting function.

Related Phrases

• "To cut with a restriction nuclease": The standard phrase describing the enzyme's primary action.

  • The vector must be cut with a restriction nuclease before ligation.

• "Restriction nuclease analysis": A technique for analyzing DNA patterns based on the fragments generated by these enzymes.

  • Restriction nuclease analysis confirmed the identity of the bacterial strain.

Noun

1. any of the enzymes that cut nucleic acid at specific restriction sites and produce restriction fragments; obtained from bacteria (where they cripple viral invaders); used in recombinant DNA technology