en·​do·​nu·​cle·​ase | \ ˌen-dō-ˈnü-klē-ˌās How to pronounce endonuclease (audio) , -ˌāz, -ˈnyü- \

Definition of endonuclease

: an enzyme that breaks down a nucleotide chain into two or more shorter chains by cleaving the internal covalent bonds linking nucleotides — compare exonuclease

Examples of endonuclease in a Sentence

Recent Examples on the Web Both circular strands of DNA are protected from endonucleases. Robert F. Service, Science | AAAS, "Forget single genes: CRISPR now cuts and splices whole chromosomes," 29 Aug. 2019 Xofluza interferes with a protein inside the flu virus called polymerase acidic endonuclease, which helps stop the virus from replicating, Dr. Adalja explains. Korin Miller, SELF, "What You Need to Know About Xofluza, the New Flu Medicine," 26 Oct. 2018 Humans don’t make UV endonuclease, either; researchers found it in a bacterium called Micrococcus luteus. Robbie Gonzalez, WIRED, "DNA-Repairing Sunscreen: Legit or Not?," 2 July 2018 Oftentimes those sequences were flanked by a set of genes coding for a class of strand-cutting enzymes called endonucleases. Megan Molteni, WIRED, "The WIRED Guide to Crispr," 27 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'endonuclease.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of endonuclease

1962, in the meaning defined above

Keep scrolling for more

Learn More about endonuclease

Time Traveler for endonuclease

Time Traveler

The first known use of endonuclease was in 1962

See more words from the same year

Statistics for endonuclease

Cite this Entry

“Endonuclease.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/endonuclease. Accessed 26 Oct. 2020.

Keep scrolling for more

More Definitions for endonuclease


en·​do·​nu·​cle·​ase | \ -ˈn(y)ü-klē-ˌās, -ˌāz How to pronounce endonuclease (audio) \

Medical Definition of endonuclease

: an enzyme that breaks down a nucleotide chain into two or more shorter chains by cleaving the internal phosphodiester bonds — see restriction endonuclease — compare exonuclease

More from Merriam-Webster on endonuclease

Britannica.com: Encyclopedia article about endonuclease

Comments on endonuclease

What made you want to look up endonuclease? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Namesakes Word Quiz

  • a citrus fruit possibly named after a person
  • Which of the following is a fruit named after a Moroccan seaport?
Spell It

Can you spell these 10 commonly misspelled words?


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!