A bacteria acquires a gene for restriction endonuclease by horizontal transfer.(AIPG -10)
|A||Bacteria will be able to destroy host DNA more efficiently|
|B||Bacteria will die due to methylase deficiency|
|C||Bacteria will multiply faster|
|D|| Proof reading improved
a. A restriction enzyme (or restriction endonuclease) is an enzyme that cuts double stranded or single stranded DNA at specific recognition nucleotide sequences known as restriction sites.
b. uch enzymes, found in bacteria, are thought to have evolved to provide a defense mechanism against invading viruses.
c. Inside a bacterial host, the restriction enzymes selectively cut up foreign DNA in a process called restriction; host (bacterial) DNA is methylated by a modification enzyme (a methylase) to protect it from the restriction enzyme’s activity.
d. By placing a methyl group on a base of the recognition site of a restriction endonuclease, methylases prevent the enzyme from cleaving the bacterial DNA and thereby protecting it.
e. Collectively, these two processes form the restriction modification system. Each restriction enzyme gene would be associated with another gene encoding the ability to produce a corresponding protective methylase enzyme.
f. In this question, the bacteria is acquiring a gene for restriction endonuclease by horizontal transfer. It is not producing the protective methylase enzyme. Hence the restriction enzyme will cleave the bacterial DNA and it will die.