轉(zhuǎn)移RNA（tRNA）是作為前體合成的,，這些前體要求在5? 和3?端進(jìn)修剪并對特定核苷酸進(jìn)行一些修飾,。Ribozyme RNase P普遍對處理tRNA的5?端負(fù)責(zé)。現(xiàn)在,，與成熟苯基丙氨酸轉(zhuǎn)移RNA 結(jié)合在一起的RNase P（來自Thermotoga maritima）的晶體結(jié)構(gòu)已被確定,。該結(jié)構(gòu)顯示了在pre-tRNA識別中所涉及的相互作用、活性點位置及催化中金屬的作用,。RNase P/tRNA核糖核蛋白結(jié)構(gòu)也為一個基于RNA的古老世界是怎樣演化為當(dāng)今由蛋白-催化劑支配的世界的提供了線索,。（生物谷Bioon.com）
Crystal structure of the T. maritima RNase P holoenzyme in complex with tRNA.
生物谷推薦原文出處：
Nature doi:10.1038/nature09516
Structure of a bacterial ribonuclease P holoenzyme in complex with tRNA
Nicholas J. Reiter,Amy Osterman,Alfredo Torres-Larios,Kerren K. Swinger,Tao Pan& Alfonso Mondragón
Ribonuclease (RNase) P is the universal ribozyme responsible for 5′-end tRNA processing. We report the crystal structure of the Thermotoga maritima RNase P holoenzyme in complex with tRNAPhe. The 154?kDa complex consists of a large catalytic RNA (P RNA), a small protein cofactor and a mature tRNA. The structure shows that RNA–RNA recognition occurs through shape complementarity, specific intermolecular contacts and base-pairing interactions. Soaks with a pre-tRNA 5′ leader sequence with and without metal help to identify the 5′ substrate path and potential catalytic metal ions. The protein binds on top of a universally conserved structural module in P RNA and interacts with the leader, but not with the mature tRNA. The active site is composed of phosphate backbone moieties, a universally conserved uridine nucleobase, and at least two catalytically important metal ions. The active site structure and conserved RNase P–tRNA contacts suggest a universal mechanism of catalysis by RNase P.
