Crystal engineering of HIV-1 reverse transcriptase for structure-based drug design.

Area of Science:

• Structural Biology
• Virology
• Drug Discovery

Background:

• HIV-1 reverse transcriptase (RT) is a key target for anti-AIDS therapies.
• High-resolution structures of RT are vital for understanding enzyme function, drug resistance, and designing inhibitors.
• Previous attempts to crystallize RT with NNRTIs like TMC278 were unsuccessful at high resolution.

Purpose of the Study:

• To develop an optimized HIV-1 RT for high-resolution crystallography.
• To obtain high-resolution structures of RT in complex with nonnucleoside reverse transcriptase inhibitors (NNRTIs).
• To facilitate the design and development of novel anti-AIDS drugs.

Main Methods:

• A systematic and iterative protein crystal engineering approach was employed.
• Engineered RT variants were created using methylated overlap-extension ligation independent cloning.
• Optimization strategies included reducing solvent content and increasing lattice contacts.

Main Results:

• Achieved diffraction of X-rays to 1.8 Å resolution for RT-TMC278 complexes.
• Obtained a high-resolution (1.85 Å) apo-RT crystal form with a distinct conformation.
• Demonstrated that engineered RTs enable rapid crystallization and high-resolution structure determination.

Conclusions:

• Protein crystal engineering is critical for obtaining high-resolution RT structures.
• Optimized RT variants facilitate the study of RT-inhibitor interactions.
• These advancements are instrumental in the development of next-generation anti-HIV drugs.