Crystal Structure of the tRNA 3′ Processing Endoribonuclease tRNase Z from Thermotoga maritima

• Published in: The Journal of biological chemistry 2005-04, Vol.280 (14), p.14138-14144
• Main Authors: Ishii, Ryohei, Minagawa, Asako, Takaku, Hiroaki, Takagi, Masamichi, Nashimoto, Masayuki, Yokoyama, Shigeyuki
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Bacterial Proteins - chemistry; Bacterial Proteins - metabolism; Base Sequence; Binding Sites; Crystallography, X-Ray; Endoribonucleases - chemistry; Endoribonucleases - metabolism; Humans; Models, Molecular; Molecular Sequence Data; Protein Folding; Protein Structure, Tertiary; RNA Processing, Post-Transcriptional; RNA, Transfer - chemistry; RNA, Transfer - metabolism; Sequence Alignment; Thermotoga maritima - enzymology; Thermotoga maritima - genetics
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M500355200

The maturation of the tRNA 3′ end is catalyzed by a tRNA 3′ processing endoribonuclease named tRNase Z (RNase Z or 3′-tRNase) in eukaryotes, Archaea, and some bacteria. The tRNase Z generally cuts the 3′ extra sequence from the precursor tRNA after the discriminator nucleotide. In contrast, Thermotoga maritima tRNase Z cleaves the precursor tRNA precisely after the CCA sequence. In this study, we determined the crystal structure of T. maritima tRNase Z at 2.6-Å resolution. The tRNase Z has a four-layer αβ/βα sandwich fold, which is classified as a metallo-β-lactamase fold, and forms a dimer. The active site is located at one edge of the β-sandwich and is composed of conserved motifs. Based on the structure, we constructed a docking model with the tRNAs that suggests how tRNase Z may recognize the substrate tRNAs.