Question

A) What is the role of Cry I Ac, Cry II Ab and Cry I Ab?
B) i) Write the sequence of restriction sites of EcoRI and give the sequence of sticky ends after EcoRI digestion.
ii) Name the source of the EcoRI restriction enzyme.

Answer 1

Hint: A genetically modified organism (GMO) is a living creature whose DNA has been changed via the use of genetic engineering techniques. Increased crop yields, lower food and drug production costs, reduced pesticide use, improved nutrient composition and food quality, pest and disease resistance, greater food security, and medical benefits to the world's growing population are some of the advantages of genetic engineering in agriculture.

Complete answer:
Let us solve this question in parts.
Part:A
Cry genes are included in Bacillus thuringiensis' genome, and they generate crystal proteins that kill a variety of insects, including cotton pests. As a result, these genes are integrated into cotton plants by genetic engineering, resulting in genetically engineered Bt Cotton plants which show resistance to insect pests.
Cotton bollworm is controlled by the Cry I Ac and Cry II Ab genes, while corn borer is controlled by the Cry I Ab gene.
Part:B
i) The restriction endonuclease EcoRI detects the ssDNA sequence $$5^{\prime }-GAATT{C}^{\prime }-3$$ and cuts the G and A nucleotides into a single strand. This recognition site is a palindrome, with the opposing strand reading $$5^{\prime }-GAATT{C}^{\prime }-3$$ and being cut in the same way. EcoRI action results in four sticky ends, as illustrated in the diagram.
ii) EcoRI enzyme is isolated from the $$RY13$$ strain of E.coli bacteria.

Note:
Restriction enzyme, also known as restriction endonuclease, is a bacterial protein that cleaves DNA at particular locations. Restriction enzymes break foreign DNA in the bacterial cell, removing invading organisms. It is used in various genetic engineering experiments and is known as the biological scissor. Genetic engineering has made significant progress in the past few decades which have benefited human lives greatly.