122. Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: Threading is a de novo protein structure prediction method suitable for sequence with
very low similarities.
Reason R: The threading method is more efficient than homology modelling.
In the light of the above statements, choose the most appropriate answer from the options given
below
1. Both A and R are correct and R is the correct explanation of A
2. Both A and R are true but R is NOT the correct explanation of A
3. A is correct but R is not correct
4. A is not correct but R is correct

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Correct Answer:

3. A is correct but R is not correct

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Explanation:

Assertion A: Threading is a de novo protein structure prediction method suitable for sequences with very low similarities.

• Correct: Threading is indeed a de novo protein structure prediction method, meaning it predicts the protein’s structure without relying on homologous structures for comparison. This method is particularly useful when the sequence has very low similarities to known protein structures, making it an ideal approach when homology modeling is not feasible.

Reason R: The threading method is more efficient than homology modeling.

• Incorrect: While threading is a valuable method, it is not necessarily more efficient than homology modeling. Homology modeling relies on the similarity between the target sequence and known protein structures, making it generally faster and more reliable when there is a good homologous structure available. Threading, on the other hand, is more computationally intensive and might not always yield better results compared to homology modeling, especially for sequences with moderate similarity to known structures.

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Conclusion:

• Threading is indeed a de novo method useful for predicting protein structures of sequences with low similarity to known proteins. However, it is not necessarily more efficient than homology modeling. Hence, while Assertion A is correct, Reason R is not a correct explanation for it.