Buck M, Griffiths E
Nucleic Acids Res. 1981 Jan 24;9(2):401-14. doi: 10.1093/nar/9.2.401.
E. coli growing rapidly in media where ferric iron is not freely available contain a population of specifically undermodified tRNAs. These tRNAs contain isopentenyl adenosine instead of the usual methylthioisopentenyl adenosine adjacent to the 3' end of the anticodon. Iron restricted E. coli also show an enhanced capacity to transport aromatic amino acids into the cell. Our work shows that undermodified tRNAs for phe, tyr and trp can function as positive regulatory elements of the aromatic amino acid transport system in E. coli. This iron related metabolic control, mediated through a specific post-transcriptional modification of the tRNAs, may be an important mechanism for adapting E. coli for growth in an iron restricted environment.
在三价铁无法自由获取的培养基中快速生长的大肠杆菌含有一群经过特殊修饰不足的转运RNA（tRNA）。这些tRNA在反密码子3'端相邻位置含有异戊烯基腺苷，而非通常的甲硫基异戊烯基腺苷。铁限制条件下的大肠杆菌还表现出将芳香族氨基酸转运到细胞内的能力增强。我们的研究表明，苯丙氨酸、酪氨酸和色氨酸的修饰不足的tRNA可作为大肠杆菌中芳香族氨基酸转运系统的正调控元件。这种通过tRNA的特定转录后修饰介导的与铁相关的代谢控制，可能是大肠杆菌适应铁限制环境生长的重要机制。
