Single-cell visual proteomics of a minimal bacterium reveals structural coordination of gene expression machineries.

Cryo-electron tomography reveals 140 structural maps of Mycoplasma pneumoniae translation phases, highlighting a supercomplex coordinating transcription, translation, and membrane attachment.

• Why it matters: Understanding how gene expression processes are structurally organized in bacteria is crucial for insights into cellular regulation and potential antimicrobial targets, yet detailed in-cell visualizations are limited.
• What they did: The study employed cryo-electron tomography on native and antibiotic-perturbed cells, capturing detailed structures of translation initiation, elongation, and recycling, and visualized transcription-translation complexes.
• The result: Findings support a threading-based reinitiation mechanism and reveal a supercomplex that links key gene expression processes, suggesting conserved regulatory strategies and advancing in-cell structural biology.