Domain assembly, surface accessibility and sequence conservation in full length HIV-1 Nef

Area of Science:

• Structural biology
• Virology
• Molecular biology

Background:

• The accessory Nef protein is essential for human immunodeficiency virus type 1 (HIV-1) replication and pathogenesis.
• Understanding Nef's structure and function is critical for developing antiviral strategies.

Purpose of the Study:

• To determine the full-length structure of the HIV-1 Nef protein (allele NL4-3).
• To model the flexible C-terminal loop involved in Nef internalization and CD4 endocytosis.
• To analyze sequence conservation across different HIV-1 strains and subtypes.

Main Methods:

• Assembly of the full-length HIV-1 Nef structure using previously solved domain structures.
• Modeling of the flexible 33-residue loop at the C-terminus.
• Sequence conservation analysis of 186 HIV-1 strains from five subtypes.
• Correlation of sequence conservation with accessible surface area and secondary structure features.

Main Results:

• The complete structure of HIV-1 Nef (allele NL4-3) was assembled, including a modeled flexible C-terminal loop.
• Sequence conservation analysis revealed significant flexibility in Nef, contributing to its extensive surface and multiple interaction sites.
• Conservation patterns were correlated with residue accessibility and secondary structure.

Conclusions:

• The structural insights into HIV-1 Nef, particularly its flexible regions, provide a basis for understanding its role in viral replication and pathogenesis.
• Sequence conservation data can guide the identification of critical residues for potential therapeutic interventions targeting Nef.