In bacteria, translation re-initiation is crucial for synthesizing proteins encoded by genes that are organized into operons. The mechanisms regulating translation re-initiation remain, however, poorly understood. We now describe the ribosome termination structure (RTS), a conserved and stable mRNA secondary structure localized immediately downstream of stop codons, and provide experimental evidence for its role in governing re-initiation efficiency in a synthetic Escherichia coli operon. We further report that RTSs are abundant, being associated with 18%–65% of genes in 128 analyzed bacterial genomes representing all phyla, and are selectively depleted when translation re-initiation is advantageous yet selectively enriched so as to insulate translation when re-initiation is deleterious. Our results support a potentially universal role for the RTS in controlling translation termination-insulation and re-initiation across bacteria.

在细菌中，翻译重新启动对于合成由组织成操纵子的基因编码的蛋白质至关重要。然而，调节翻译重新启动的机制仍然知之甚少。我们现在描述核糖体终止结构 (RTS)，一种位于终止密码子下游的保守且稳定的 mRNA 二级结构，并为其在合成大肠杆菌中控制重新启动效率的作用提供实验证据操纵子。我们进一步报告说，RTS 是丰富的，与代表所有门的 128 个分析的细菌基因组中 18%–65% 的基因相关，并且在翻译重新启动有利时被选择性消耗，但选择性地富集以在重新启动时隔离翻译是有害的。我们的结果支持 RTS 在控制翻译终止-绝缘和跨细菌重新启动方面的潜在普遍作用。