期刊
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
卷 108, 期 18, 页码 7368-7372出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.1018636108
关键词
biochemistry; queuosine; reductive dehalogenation
资金
- National Institutes of Health (NIH) [GM72623, T32 GM008804]
- Burroughs Wellcome Fund
- National Science Foundation [0654435]
- Division Of Graduate Education
- Direct For Education and Human Resources [0654435] Funding Source: National Science Foundation
Transfer RNA is one of the most richly modified biological molecules. Biosynthetic pathways that introduce these modifications are underexplored, largely because their absence does not lead to obvious phenotypes under normal growth conditions. Queuosine (Q) is a hypermodified base found in the wobble positions of tRNA Asp, Asn, His, and Tyr from bacteria to mankind. Using liquid chromatography MS methods, we have screened 1,755 single gene knockouts of Escherichia coli and have identified the key final step in the biosynthesis of Q. The protein is homologous to B12-dependent iron-sulfur proteins involved in halorespiration. The recombinant Bacillus subtilis epoxyqueuosine (oQ) reductase catalyzes the conversion of oQ to Q in a synthetic substrate, as well as undermodified RNA isolated from an oQ reductase knockout strain. The activity requires inclusion of a reductant and a redox mediator. Finally, exogenously supplied cobalamin stimulates the activity. This work provides the framework for studies of the biosynthesis of other modified RNA components, where lack of accessible phenotype or obvious gene clustering has impeded discovery. Moreover, discovery of the elusive oQ reductase protein completes the biosynthetic pathway of Q.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据