Solving the structure of Escherichia coli elongation factor Tu using a twinned data set

Area of Science:

• Structural biology
• Crystallography
• Molecular biology

Background:

• Escherichia coli elongation factor Tu (EF-Tu) is crucial for protein synthesis.
• Investigating EF-Tu interactions with novel inhibitors is key to understanding its function and developing therapeutics.
• Crystallization of protein-inhibitor complexes can be challenging due to crystal defects.

Purpose of the Study:

• To determine the presence of novel inhibitors within crystallized EF-Tu-GDP.
• To elucidate the three-dimensional structure of EF-Tu-GDP in the presence of inhibitors.
• To characterize new packing arrangements of EF-Tu-GDP dimers.

Main Methods:

• Crystallization of EF-Tu-GDP with novel inhibitors.
• X-ray diffraction data collection and processing, even from poor-quality, twinned, and mosaic crystals.
• 3D structure determination using X-ray diffraction data.

Main Results:

• Successfully obtained and processed X-ray diffraction data from epitaxially and merohedrally twinned, highly mosaic EF-Tu-GDP crystals.
• Determined the presence of inhibitors within the crystal structure.
• Solved the 3D structure of EF-Tu-GDP, revealing a novel dimer packing.

Conclusions:

• The study successfully determined the presence of inhibitors bound to EF-Tu-GDP.
• The structural analysis revealed a previously undescribed dimer organization for EF-Tu-GDP.
• This work provides insights into EF-Tu-GDP inhibition and structural dynamics.