替代性tRNA的三级结构,以便通过转录后修饰酶进行识别
Ryuichiro Ishitani1, Osamu Nureki, Nobukazu Nameki
1Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Cell
|May 7, 2003
概括
转移RNA (tRNA) 采用一种新的"lambda形式"进行修改. 这种结构暴露了G15,使酶能够访问并修改tRNA核心.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 转移RNA (tRNA) 通常表现为三叶草状的二级结构和L形的三级结构.
- 转录后修改对tRNA稳定性至关重要,但酶在L形式中面临着可访问性挑战.
研究的目的:
- 阐明通过archaeosine tRNA-guanine transglycosylase进行tRNA修饰的结构机制.
- 了解酶如何访问tRNA中埋藏的核酸.
主要方法:
- 结晶结构的确定与archaeosine tRNA-guanine transglycosylase结合的tRNA.
主要成果:
- 这种tRNA采用了另一种"lambda形式"的形状,与正规的L形式不同.
- 这种lambda形式破坏了D臂内规范的二次基对和三级相互作用.
- D臂变得单链,突出,暴露G15的酶访问.
结论:
- tRNA的"lambda形式"对于精确的G15酶修饰至关重要.
- 这种形状变化克服了tRNA中修改核心核酸的可访问性悖论.
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01:23RNA Structure
Overview
The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
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