Question

The restriction enzyme responsible for the cleavage of the following sequence is
\[\begin{align}
  & 5\text{ }\text{ }G\text{ }\text{ }T\text{ }\text{ }C\text{ }\text{ }G\text{ }\text{ }A\text{ }\text{ }C\text{ }\text{ }3 \\
 & 3\text{ }\text{ }C\text{ }\text{ }A\text{ }\text{ }G\text{ }\text{ }C\text{ }\text{ }T\text{ }\text{ }G\text{ }\text{ }5 \\
\end{align}\]
A) Alu I
B) Bam HI
C) Hind II
D) Eco RI

Answer 1

Hint: Restriction enzymes are enzymes used to cut the DNA at specific points. These specific points are known as recognition sites. Every restriction enzyme has a unique recognition site.

Complete answer:
a) Alu I:
Alu I stand for Arthrobacter luteus because the restriction enzyme Alu I has been originated from the Arthrobacter luteus bacteria. The recognition site for the Alu I restriction enzyme is:
\[\begin{array}{*{35}{l}}
   5\text{ }\text{ }G\text{ }\text{ }T\text{ }\text{ }C\text{ }\text{ }G\text{ }\text{ }A\text{ }\text{ }C\text{ }\text{ }3 \\
   3\text{ }\text{ }C\text{ }\text{ }A\text{ }\text{ }G\text{ }\text{ }C\text{ }\text{ }T\text{ }\text{ }G\text{ }\text{ }5 \\
\end{array}\]
This restriction enzyme produces blunt or flush ends.
b) Bam HI:
Bam HI stands for Bacillus amyloliquefaciens because the restriction enzyme Bam HI has been derived from the Bacillus amyloliquefaciens bacteria. The recognition site of the Bam HI restriction enzyme is:
\[\begin{array}{*{35}{l}}
   5\text{ }\text{ }G\text{ }\text{ }G\text{ }\text{ }A\text{ }\text{ }T\text{ }\text{ }C\text{ }\text{ }C\text{ }\text{ }3 \\
   3\text{ }\text{ }C\text{ }\text{ }C\text{ }\text{ }T\text{ }\text{ }A\text{ }\text{ }G\text{ }\text{ }G\text{ }\text{ }5 \\
\end{array}\]
This restriction enzyme produces sticky or cohesive ends.
c) Hind II:
Hind II stands for Haemophilus influenzae because the restriction enzyme Hind II originated from the Haemophilus influenzae bacteria. The recognition site for the Hind II restriction enzyme is:
\[\begin{array}{*{35}{l}}
   5\text{ }\text{ }G\text{ }\text{ }A\text{ }\text{ }A\text{ }\text{ }T\text{ }\text{ }T\text{ }\text{ }C\text{ }\text{ }3 \\
   3\text{ }\text{ }C\text{ }\text{ }T\text{ }\text{ }T\text{ }\text{ }A\text{ }\text{ }A\text{ }\text{ }G\text{ }\text{ }5 \\
\end{array}\]
This restriction enzyme produces Blunt or Flush ends.
d) Eco RI:
Eco RI stands for Escherichia coli. The recognition site for the Eco RI restriction enzyme is:
\[\begin{array}{*{35}{l}}
   5\text{ }\text{ }G\text{ }\text{ }A\text{ }\text{ }A\text{ }\text{ }T\text{ }\text{ }T\text{ }\text{ }C\text{ }\text{ }3 \\
   3\text{ }\text{ }C\text{ }\text{ }T\text{ }\text{ }T\text{ }\text{ }A\text{ }\text{ }A\text{ }\text{ }G\text{ }\text{ }5 \\
\end{array}\]
This restriction enzyme produces sticky or cohesive ends.
Thus, based on the above information, we can conclude that the restriction enzyme responsible for the cleavage of the sequence
\[\begin{array}{*{35}{l}}
   5\text{ }\text{ }G\text{ }\text{ }T\text{ }\text{ }C\text{ }\text{ }G\text{ }\text{ }A\text{ }\text{ }C\text{ }\text{ }3 \\
   3\text{ }\text{ }C\text{ }\text{ }A\text{ }\text{ }G\text{ }\text{ }C\text{ }\text{ }T\text{ }\text{ }G\text{ }\text{ }5 \\
\end{array}\]
is Alu I.
Hence, the correct answer is option A.

Note: Restriction enzymes serve as the chemical knives to cut the DNA or the genes into specified or defined segments. Also, the restriction enzymes are obtained only from the prokaryotic organisms because these enzymes are the natural defence mechanism of the bacteria against bacteriophage infections.