Summary information and primary citation

PDB-id
3wfq; SNAP-derived features in text and JSON formats; DNAproDB
Class
transferase-RNA
Method
X-ray (3.619 Å)
Summary
Trna processing enzyme complex 1
Reference
Yamashita S, Takeshita D, Tomita K (2014): "Translocation and rotation of tRNA during template-independent RNA polymerization by tRNA nucleotidyltransferase." Structure, 22, 315-325. doi: 10.1016/j.str.2013.12.002.
Abstract
The 3'-terminal CCA (CCA-3' at positions 74-76) of tRNA is synthesized by CCA-adding enzyme using CTP and ATP as substrates, without a nucleic acid template. In Aquifex aeolicus, CC-adding and A-adding enzymes collaboratively synthesize the CCA-3'. The mechanism of CCA-3' synthesis by these two enzymes remained obscure. We now present crystal structures representing CC addition onto tRNA by A. aeolicus CC-adding enzyme. After C74 addition in an enclosed active pocket and pyrophosphate release, the tRNA translocates and rotates relative to the enzyme, and C75 addition occurs in the same active pocket as C74 addition. At both the C74-adding and C75-adding stages, CTP is selected by Watson-Crick-like hydrogen bonds between the cytosine of CTP and conserved Asp and Arg residues in the pocket. After C74C75 addition and pyrophosphate release, the tRNA translocates further and drops off the enzyme, and the CC-adding enzyme terminates RNA polymerization.

Cartoon-block schematics in six views (download the tarball)

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