Was the first restriction enzyme found in what organism?

Question

was it e.coli or Haemophilus influenzae bacteria? thanks!

Answer 1

The first restriction enzyme to be isolated was that from E. coli K laboratory strains in 1968 (Meselson and Yuan, 1968). This enzyme was able to cleave DNA, but the precise site of DNA cleavage remained unclear. The enzyme displayed a number of complex activities that made it difficult to study.

In 1970, Hamilton Smith and his coworkers isolated a restriction enzyme activity from the bacterium Haemophilus influenzae strain Rd and showed that it was able to cleave DNA at specific sites. The enzyme, called HindII, recognizes a six-base-pair double-stranded DNA sequence of S'-G-T-pyrimidine-purine-A-C-3':

5'-GT(T/C)| (G/A)AC-3'

3'-CA(A/G)| (C/T)TG -5'

http://www.dpo.uab.edu/~abej/BY431/(16)%...

Answer 2

E.coli

The Nobel Prize in Medicine was awarded, in 1978, to Daniel Nathans, Werner Arber, and Hamilton Smith for the discovery of restriction endonucleases. Their discovery lead to the development of recombinant DNA technology that allowed, for example, the large scale production of human insulin for diabetics using E. coli bacteria. Over 100 restriction enzymes have since been purified and characterized from different types and strains of bacteria, and are routinely used for DNA modification and manipulation in laboratories