As ancient bacterial endosymbionts of eukaryotic cells, mitochondria have retained their own circular DNA as well as protein translation system including mitochondrial ribosomes (mitoribosomes). In recent years, methodological advancements in cryoelectron microscopy and mass spectrometry have revealed the extent of the evolutionary divergence of mitoribosomes from their bacterial ancestors and their adaptation to the synthesis of 13 mitochondrial DNA encoded oxidative phosphorylation complex subunits. In addition to the structural data, the first assembly pathway maps of mitoribosomes have started to emerge and concomitantly also the assembly factors involved in this process to achieve fully translational competent particles. These transiently associated factors assist in the intricate assembly process of mitoribosomes by enhancing protein incorporation, ribosomal RNA folding and modification, and by blocking premature or non-native protein binding, for example. This review focuses on summarizing the current understanding of the known mammalian mitoribosome assembly factors and discussing their possible roles in the assembly of small or large mitoribosomal subunits.

作为真核细胞的古老细菌内共生体，线粒体保留了自己的环状DNA以及包括线粒体核糖体（mitoribosomes）在内的蛋白质翻译系统。近年来，低温电子显微镜和质谱技术的进步揭示了线粒体核糖体与其细菌祖先的进化分化程度以及它们对合成 13 个线粒体 DNA 编码的氧化磷酸化复合物亚基的适应性。除了结构数据之外，第一个核糖体组装途径图已经开始出现，并且伴随着该过程中涉及的组装因素也开始出现，以实现完全翻译的能力粒子。例如，这些瞬时相关因素通过增强蛋白质掺入、核糖体 RNA 折叠和修饰，以及通过阻断过早或非天然蛋白质结合来协助线粒体核糖体的复杂组装过程。这篇综述的重点是总结目前对已知哺乳动物线粒体核糖体组装因子的理解，并讨论它们在小或大线粒体亚基组装中的可能作用。