Question

The letter 'R' in EcoRI is derived from
(a)The name of the genus
(b)The name of the strain
(c)The name of species
(d)None of the above

Answer 1

Hint: EcoRI endonuclease is a globular type restriction enzyme that is found in the bacteria Escherichia coli. This endonuclease particularly acts as a defense mechanism, to protect the organism from invading foreign DNA.

Complete answer:
EcoRI also pronounced as "eco R one" is a restriction endonuclease enzyme isolated from the species E. coli. The Eco part of the enzyme is derived from the species from which it was isolated, while the R represents the particular strain, in this case, RY13.In EcoRI, "E" denotes the generic name which is "Escherichia" while "co" denotes the species name which is "coli" The last part of its name, the I, denotes that it was the first enzyme which was isolated from this strain. EcoRI is basically a restriction enzyme that cleaves DNA double helices into fragments at specific sites.

Additional Information: In molecular biology, EcoRI is used as a restriction enzyme. EcoRI creates mainly 4 nucleotide sticky ends with 5' end overhangs of AATT. The nucleic acid recognition site where the enzyme cuts are G/AATTC, which has a palindromic, complementary sequence of CTTAA/G. The ‘/’ within the sequence specifies which phosphodiester bond the enzyme will break in the DNA molecule. Restriction enzymes, like EcoRI, are used in a wide range of molecular techniques related to genetics including cloning, DNA screening, and deleting sections of DNA in vitro. Restriction enzymes, like EcoRI that specifically produce sticky ends of DNA, are often used to cut DNA prior to ligation, as the sticky ends make the ligation reaction more efficient. EcoRI can show non-site-specific cutting, known as star activity, depending on the conditions present in the reaction.
So, the correct answer is 'The name of strain'.

Note: Hamilton O. Smith, Thomas Kelly, and Kent Wilcox in 1970, isolated and characterized the first most type II restriction enzyme. It was termed as HindII, from the bacterium Haemophilus influenzae.