Which one of the sequences given below is a portion of a potential microRNA precursor?

Correct option is D

Precursor microRNAs (pre-miRNAs) are typically characterized by a stem-loop structure, which is crucial for their function. In this case, the sequence in option 4 is indicative of a potential pre-miRNA. The sequence forms a stem-loop structure, with a characteristic double-stranded stem and a single-stranded loop. This structure is required for recognition and processing by the Dicer enzyme to form mature miRNAs, which play a role in regulating gene expression post-transcriptionally.

Information Booster:

1. MicroRNAs are small RNA molecules that regulate gene expression by binding to complementary mRNA sequences, leading to mRNA degradation or inhibition of translation.

2. Pre-miRNA typically forms a stem-loop structure, which is recognized by Dicer for processing.

3. Precursor miRNAs are usually around 60-70 nucleotides long and include both a stem (double-stranded) and a loop (single-stranded).

4. After Dicer processes the pre-miRNA, a mature miRNA is produced, which becomes part of the RNA-induced silencing complex (RISC).

5. miRNAs are involved in controlling a variety of biological processes, including cell differentiation, proliferation, and apoptosis.

6. The stem-loop structure in option 4 fits the characteristics of a potential pre-miRNA, indicating it can be processed into a mature miRNA.