Question

In the nomenclature of enzyme, restriction endonuclease, the Roman numeral indicates

• A. Number of times it is used
• B. The order of discovery from source
• C. Number of cuts on DNA
• D. Number of recombinants formed

Answer 1

The correct option is B The order of discovery from source

Restriction enzymes are named based on the organism in which they were discovered. The first three letters of the name are italicized because they abbreviate the genus and species names of the organism. The fourth letter comes from the bacterial strain designation. The Roman numerals are used to identify specific enzymes from bacteria that contain multiple restriction enzymes. Typically, the Roman numeral indicates the order in which restriction enzymes were discovered in a particular strain.