Conformational Analysis and Structure-Altering Mutations of the HIV-1 Frameshifting Element

Area of Science:

• Molecular Biology
• Virology
• Computational Biology

Background:

• Human Immunodeficiency Virus type 1 (HIV-1) poses a significant public health challenge.
• Targeting ribosomal frameshifting is a promising strategy against HIV-1.
• The HIV-1 RNA frameshift element (FSE) plays a crucial role in viral replication.

Purpose of the Study:

• To investigate how sequence context and length influence the folding patterns of the HIV-1 FSE.
• To identify specific mutations that alter HIV-1 FSE structure and frameshifting efficiency.
• To lay the groundwork for computational and experimental analysis of the HIV-1 FSE.

Main Methods:

• Utilized RNA-As-Graphs (RAG), a graph-theory framework, for RNA secondary structure analysis.
• Performed SHAPE-guided 2D-fold predictions on the HIV-1 FSE with varying sequence lengths.
• Predicted structure-altering mutations within the FSE.

Main Results:

• The core HIV-1 FSE exhibits a stable upper stem and a flexible lower stem, connected by a three-way junction.
• Little evidence for pseudoknot or triplex interactions within the core FSE was found.
• Pseudoknots can form in longer sequences as connective motifs.
• Identified sensitive residues in the upper stem and central loop that impact core stem-loop folding.

Conclusions:

• Understanding the HIV-1 FSE's fold and identifying structure-altering mutations are critical for therapeutic development.
• These findings support further all-atom simulations and experimental validation.
• The study advances mechanistic understanding and potential therapeutic strategies for HIV-1.