ジャーナル: Science / 年: 2018 タイトル: Structural insight into precursor tRNA processing by yeast ribonuclease P. 著者: Pengfei Lan / Ming Tan / Yuebin Zhang / Shuangshuang Niu / Juan Chen / Shaohua Shi / Shuwan Qiu / Xuejuan Wang / Xiangda Peng / Gang Cai / Hong Cheng / Jian Wu / Guohui Li / Ming Lei / 要旨: Ribonuclease P (RNase P) is a universal ribozyme responsible for processing the 5'-leader of pre-transfer RNA (pre-tRNA). Here, we report the 3.5-angstrom cryo-electron microscopy structures of ...Ribonuclease P (RNase P) is a universal ribozyme responsible for processing the 5'-leader of pre-transfer RNA (pre-tRNA). Here, we report the 3.5-angstrom cryo-electron microscopy structures of RNase P alone and in complex with pre-tRNA The protein components form a hook-shaped architecture that wraps around the RNA and stabilizes RNase P into a "measuring device" with two fixed anchors that recognize the L-shaped pre-tRNA. A universally conserved uridine nucleobase and phosphate backbone in the catalytic center together with the scissile phosphate and the O3' leaving group of pre-tRNA jointly coordinate two catalytic magnesium ions. Binding of pre-tRNA induces a conformational change in the catalytic center that is required for catalysis. Moreover, simulation analysis suggests a two-metal-ion S2 reaction pathway of pre-tRNA cleavage. These results not only reveal the architecture of yeast RNase P but also provide a molecular basis of how the 5'-leader of pre-tRNA is processed by eukaryotic RNase P.