# DBT JRF 2022 — Question 120

Exam: DBT JRF 2022 · Section: B · Topic: Bioinformatics › RNA Structural Interactions · Difficulty: Medium

## Question

Which one of the following DOES NOT represent known interactions of RNA secondary structural elements?

## Options

- **A.** Pseudo knot
- **B.** Kissing hairpins
- **C.** Hairpin-bulge contact
- **D.** Helix-turn-helix

## Answer

Option D

## Explanation

RNA secondary structural interactions — identifying the non-RNA motif: Known RNA-RNA interaction motifs and secondary structural elements: • Pseudoknots: tertiary/secondary structure where a loop base-pairs with a region outside the stem, creating a knotted-like structure. Found in ribozymes, ribosomal RNA, telomerase RNA. • Kissing hairpins: Two hairpin loops base-pair with each other through complementary sequences in their loop regions. Important in HIV dimerisation and translational regulation. • Hairpin-bulge contacts: A hairpin loop makes tertiary contact with a bulge in another stem; common in ribosomal RNA. • Helix-turn-helix (HTH): A DNA-BINDING PROTEIN MOTIF (found in transcription factors, homeodomain proteins). NOT an RNA secondary structural interaction — it is a protein fold element. Answer: Helix-turn-helix is a DNA-binding protein motif, NOT an RNA secondary structural interaction.

Source: https://mypyqbuddy.com/questions/which-one-of-the-following-does-not-represent-6a104cd5920734408bc0c787