5HC9

Thermotoga maritima CCA-adding enzyme complexed with tRNA_CCA

Summary for 5HC9

• Entry DOI: 10.2210/pdb5hc9/pdb
• Related: 3H38
• Descriptor: tRNA nucleotidyl transferase-related protein, tRNAphe, MAGNESIUM ION (3 entities in total)
• Functional Keywords: trna, cca-adding enzyme, transferase
• Biological source: Thermotoga maritima (strain ATCC 43589 / MSB8 / DSM 3109 / JCM 10099); More
• Total number of polymer chains: 4
• Total formula weight: 152078.95

Authors

Yamashita, S.,Tomita, K. (deposition date: 2016-01-04, release date: 2016-04-27, Last modification date: 2023-11-08)

Primary citation

Yamashita, S.,Tomita, K.
Mechanism of 3'-Matured tRNA Discrimination from 3'-Immature tRNA by Class-II CCA-Adding Enzyme
Structure, 24:918-925, 2016

PubMed Abstract: CCA-adding enzyme adds the 3'-CCA of tRNA, using CTP and ATP as substrates, and terminates RNA synthesis after completion of CCA addition, without using a nucleic acid template. The complex structure of class-II Thermotoga maritima CCA-adding enzyme and mature tRNA with 3'-CCA revealed the mechanisms by which the enzyme terminates RNA synthesis after completion of 3'-CCA addition, and discriminates 3'-mature tRNA from 3'-immature tRNA. After completion of 3'-CCA addition at the catalytic site, the 3'-CCA refolds and relocates to the release site, which is discrete from the catalytic site. The 3'-CCA forms a continuously stacked, stable conformation together with the enzyme. Consequently, the 3'-mature tRNA rotates relative to the surface of the enzyme, and only the 3'-mature tRNA is ready for release. The 3'-regions of immature tRNAs cannot form the stable stacking conformation in the release site; thus, the 3' end is relocated in the catalytic site, and the 3'-CCA is reconstructed.

PubMed: 27133023
DOI: 10.1016/j.str.2016.03.022

Experimental method

X-RAY DIFFRACTION (2.9 Å)