biostudies-literatureDu MGuangdong Innovative and Entrepreneurial Research Team ProgramGuangdong ProgramGuangdong Basic and Applied Basic Research FoundationNational Natural Science Foundation of ChinaShenzhen Science and Technology Program7947-7960https://www.ebi.ac.uk/biostudies/studies/S-EPMC11260487biostudies-literatureUnknown52(13)Ribosome biogenesis is a highly regulated cellular process that involves the control of numerous assembly factors. The small protein YjgA has been reported to play a role in the late stages of 50S assembly. However, the precise molecular mechanism underlying its function remains unclear. In this study, cryo-electron microscopy (cryo-EM) structures revealed that depletion of YjgA or its N-terminal loop in Escherichia coli both lead to the accumulation of immature 50S particles with structural abnormalities mainly in peptidyl transferase center (PTC) and H68/69 region. CryoDRGN analysis uncovered 8 and 6 distinct conformations of pre50S for ΔyjgA and YjgA-ΔNloop, respectively. These conformations highlighted the role of the N-terminal loop of YjgA in integrating uL16 and stabilizing H89 in PNucleic acids researchYjgA plays dual roles in enhancing PTC maturation.PMC112604872021ZT09Y1042021A15150108052021QN02Y35332171200JCYJ2022053011521002392169111Deng CZhou QYu TZeng FDu MfalseYjgA plays dual roles in enhancing PTC maturation.Ribosome biogenesis is a highly regulated cellular process that involves the control of numerous assembly factors. The small protein YjgA has been reported to play a role in the late stages of 50S assembly. However, the precise molecular mechanism underlying its function remains unclear. In this study, cryo-electron microscopy (cryo-EM) structures revealed that depletion of YjgA or its N-terminal loop in Escherichia coli both lead to the accumulation of immature 50S particles with structural abnormalities mainly in peptidyl transferase center (PTC) and H68/69 region. CryoDRGN analysis uncovered 8 and 6 distinct conformations of pre50S for ΔyjgA and YjgA-ΔNloop, respectively. These conformations highlighted the role of the N-terminal loop of YjgA in integrating uL16 and stabilizing H89 in P2024-01-01T00:00:00Z2024 Jul2026-06-01T20:36:56.746Z2025-05-18T13:26:19.816ZS-EPMC112604873884293210.1093/nar/gkae469