Structure of a bacterial ribonuclease P holoenzyme in complex with tRNA

Article

关键词: PRECURSOR TRANSFER-RNA;    CRYSTAL-STRUCTURE;    ESCHERICHIA-COLI;    2-METAL-ION MECHANISM;    THERMOTOGA-MARITIMA;    PROTEIN-COMPONENT;    CONSERVED CORE;    BINDING-SITE;    ACTIVE-SITE;    SUBSTRATE;   

DOI  :  10.1038/nature09516

来源: SCIE

【 摘 要 】

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 tRNA(Phe). 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.

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