Lohse P A, Szostak J W
Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114, USA.
Nature. 1996 May 30;381(6581):442-4. doi: 10.1038/381442a0.
The 'RNA world' hypothesis proposes an early stage in the evolution of life in which both genomic and catalytic functions were fulfilled by RNA. The evolution of RNA-catalysed protein synthesis would have been a necessary step in the transition from such an RNA world to modern protein-dominated biology. For this to have been possible, RNA must be capable of catalysing amide-bond formation using acylated carrier RNA substrates as amino-acid donors. We have used in vitro selection and evolution to isolate ribozymes with acyl transferase activity from a pool of random RNA sequences. One of these acyl transferases with a 5'-amino group transfers an amino acid to itself in a reaction that we propose to be analogous to peptidyl transfer on the ribosome.
“RNA世界”假说提出了生命进化的早期阶段，在这一阶段，基因组功能和催化功能均由RNA实现。RNA催化的蛋白质合成的进化，本应是从这样一个RNA世界向现代以蛋白质为主导的生物学转变的必要步骤。要实现这一点，RNA必须能够使用酰化载体RNA底物作为氨基酸供体来催化酰胺键的形成。我们利用体外筛选和进化技术，从随机RNA序列库中分离出具有酰基转移酶活性的核酶。这些酰基转移酶中的一种带有5'-氨基，在一个我们认为类似于核糖体上肽基转移的反应中，将氨基酸转移到自身。
