Structural basis of ribosome maturation and translational recovery in E. coli lacking RimM maturation factor
| Autoři | |
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| Rok publikování | 2025 |
| Druh | Konferenční abstrakty |
| Fakulta / Pracoviště MU | |
| Citace | |
| Přiložené soubory | |
| Popis | Ribosome assembly and maturation is a highly complex and multistep process that begins with the folding and modification of ribosomal RNA (rRNA), followed by the sequential assembly and integration of ribosomal proteins. Numerous biogenesis factors play crucial roles in orchestrating this process, ensuring the proper formation of functional ribosomal subunits. Disruptions or alterations in these factors can lead to severe growth defects and the accumulation of immature ribosomal subunits. The ribosome maturation factor RimM is important for the proper assembly of the 30S small ribosomal subunit. In E. coli, the deletion of the rimM gene results in a reduced growth rate, the accumulation of immature 30S particles, and decreased translational efficiency. However, the gradual restoration of bacterial growth suggests the activation of compensatory mechanisms that help recover translation capacity over time. One potential mechanism can involve the ribosomal silencing factor RsfS, which plays a crucial role in regulating protein synthesis by binding to the 50S ribosomal subunit. This interaction inhibits the premature assembly of 70S ribosomes, potentially preventing the association of mature 50S subunits with immature 30S particles. Here, we explored the coordinated actions of RsfS and translation initiation factors in maintaining translational efficiency in the absence of RimM. High-resolution cryo-EM analysis reveals that translation initiation factors bind to immature 30S subunits, preventing their association with 50S subunits until ribosomal proteins are fully assembled. Simultaneously, RsfS binds to the 50S subunit, thereby inhibiting the formation of 70S ribosomes. Our findings provide structural and mechanistic insights into the final stages of ribosome assembly and highlight the critical roles of ribosome-associated factors in ensuring translational fidelity. |
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