Site-specific solid-state NMR studies of "trigger factor" in complex with the large ribosomal subunit 50S

Area of Science:

• Structural Biology
• Biophysics
• Molecular Machines

Background:

• Co-translational protein folding remains poorly understood.
• High-resolution ribosome structures exist, but dynamic processes are unclear.

Purpose of the Study:

• To investigate the mechanism of co-translational protein folding.
• To present the first solid-state NMR data on non-mobile regions of a prokaryotic ribosomal complex.

Main Methods:

• Utilized solid-state NMR spectroscopy.
• Employed proton detection and high magic angle spinning (MAS) frequencies (60 kHz).
• Analyzed a large asymmetric protein complex (1.4 MDa).

Main Results:

• Observed localized chemical shift perturbations and line broadening in backbone amide resonances.
• Identified trigger factor ribosome-binding domain regions in direct contact or undergoing conformational changes.
• Demonstrated NMR accessibility for large macromolecular complexes.

Conclusions:

• Solid-state NMR provides insights into co-translational protein folding.
• The findings illuminate the interaction between trigger factor and the ribosome.
• Opens new avenues for studying large molecular machinery mechanisms.