Question

If a gene contains the sequence TACAATCGCATTGAA, what antisense RNA could be used to stop translation directly?

Short answer

The antisense RNA that could be used to stop translation directly, corresponding to the DNA sequence TACAATCGCATTGAA, is AUGUUAGCGUAA CUU.

Step-by-step solution

Identify the DNA Sequence

Note the DNA sequence provided in the exercise: TACAATCGCATTGAA.

Apply Pairing Rules to Generate Antisense RNA

Apply the base pairing rules to each nucleotide in the sequence to generate the antisense RNA. Pair A with U, T with A, and C with G. Doing so, the antisense RNA sequence complementary to the given DNA sequence is AUGUUAGCGUAA CUU.

Confirm the Sequence

Confirm the sequence. Always double check the antisense RNA sequence against the original DNA sequence by ensuring each nucleotide correctly pairs with its complement.

Key concepts

Understanding the DNA Sequence

DNA, or deoxyribonucleic acid, is the molecule that carries our genetic instructions. It is composed of long chains of nucleotides, each containing a sugar, phosphate group, and one of four nitrogenous bases. These bases are abbreviated as A (adenine), T (thymine), C (cytosine), and G (guanine). The specific order of these bases in a strand of DNA the DNA sequence determines what genetic information is carried.

• The sequence TACAATCGCATTGAA represents a section of a DNA molecule.
• This sequence is written from the 5' (five prime) end to the 3' (three prime) end, a convention used to denote the directionality of the DNA strand.

Understanding the DNA sequence is crucial because it is the template from which RNA is synthesized during the process known as transcription. From here, these instructions can translate into functional proteins.

Exploring Base Pairing Rules

Base pairing is a fundamental principle of DNA and RNA structure. In DNA, each base pairs with a specific complementary partner:

• Adenine (A) pairs with Thymine (T)
• Cytosine (C) pairs with Guanine (G)

The concept of base pairing is slightly different in RNA, as thymine is replaced with uracil (U). Therefore, the base pairing rules for DNA to RNA are:

• Adenine (A) pairs with Uracil (U)
• Thymine (T) pairs with Adenine (A)
• Cytosine (C) pairs with Guanine (G)
• Guanine (G) pairs with Cytosine (C)

When creating an antisense RNA strand, which is designed to bind to and inhibit the sense (or coding) RNA, these rules are used to determine the correct sequence. For the DNA sequence TACAATCGCATTGAA, following these rules forms the antisense RNA sequence AUGUUAGCGUAACUU.

Mechanism of Gene Translation Inhibition

Gene translation inhibition is a process where the production of proteins from genes is halted or reduced. This can occur through various mechanisms, but antisense RNA is a common tool used to inhibit translation directly.

• Translation is the process by which ribosomes read mRNA sequences to synthesize proteins. mRNA is "messenger" RNA, which serves as the direct template for protein production.
• Antisense RNAs are strands complementary to mRNA sequences that bind to their target mRNAs through base pairing.
• Upon binding, antisense RNAs prevent ribosomes from attaching to the mRNA, thereby blocking the translation process.
• As a result, the gene tied to the mRNA is effectively "silenced": no protein is produced, which can be useful in research or therapy contexts to understand gene function or treat diseases.

This method's specificity arises from the high fidelity of base pairing, ensuring the antisense RNA only binds to its intended mRNA target. With careful design, researchers can use antisense RNA to precisely inhibit gene translation, turning off specific genes as needed.