Ribozyme-Catalyzed Aminoacylation from CoA Thioesters
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- 作者：Na Li and Faqing Huang
- 刊名：Biochemistry
- 出版年：2005
- 出版时间：March 22, 2005
- 年：2005
- 卷：44
- 期：11
- 页码：4582 - 4590
- 全文大小：300K
- 年卷期：v.44,no.11(March 22, 2005)
- ISSN：1520-4995
文摘
Coenzyme A (CoA) thioesters play essential roles in modern metabolism. To demonstrateplausible biochemical functions of thioesters in the RNA world, we have isolated a new class of ribozymes(ACT) that catalyze self-aminoacylation from a number of CoA thioesters with catalytic efficiencies rangingfrom 7000 to 24 000 M-1·min-1. Active thioester substrates are required to contain both a free 
-aminogroup in the acyl moiety and a CoA as the thiol component. We hypothesize ribozyme-based aminoacylationsystems using aminoacyl thioesters of CoA as the ancestors of modern aminoacyl tRNA synthetases. Onthe basis of our previous results [Huang et al. (2000) Biochemistry 39, 15548-15555; Coleman and Huang(2002) Chem. Biol. 9, 1227-1236], an extensive RNA-catalyzed "metabolic pathway" involving CoAand its thioesters is proposed. Complex contemporary metabolic systems could have evolved from theproposed ribozyme pathways.
-aminogroup in the acyl moiety and a CoA as the thiol component. We hypothesize ribozyme-based aminoacylationsystems using aminoacyl thioesters of CoA as the ancestors of modern aminoacyl tRNA synthetases. Onthe basis of our previous results [Huang et al. (2000) Biochemistry 39, 15548-15555; Coleman and Huang(2002) Chem. Biol. 9, 1227-1236], an extensive RNA-catalyzed "metabolic pathway" involving CoAand its thioesters is proposed. Complex contemporary metabolic systems could have evolved from theproposed ribozyme pathways.