3H3A

The complex structure of CCA-adding enzyme with CTP

Summary for 3H3A

• Entry DOI: 10.2210/pdb3h3a/pdb
• Related: 3H37 3H38 3H39
• Descriptor: TRNA nucleotidyl transferase-related protein, CYTIDINE-5'-TRIPHOSPHATE (3 entities in total)
• Functional Keywords: transferase/rna, nucleotide-binding, nucleotidyltransferase, rna-binding, transferase
• Biological source: Thermotoga maritima
• Total number of polymer chains: 2
• Total formula weight: 104027.55

Authors

Toh, Y.,Tomita, K. (deposition date: 2009-04-16, release date: 2009-10-13, Last modification date: 2023-11-01)

Primary citation

Toh, Y.,Takeshita, D.,Numata, T.,Fukai, S.,Nureki, O.,Tomita, K.
Mechanism for the definition of elongation and termination by the class II CCA-adding enzyme
Embo J., 28:3353-3365, 2009

PubMed Abstract: The CCA-adding enzyme synthesizes the CCA sequence at the 3' end of tRNA without a nucleic acid template. The crystal structures of class II Thermotoga maritima CCA-adding enzyme and its complexes with CTP or ATP were determined. The structure-based replacement of both the catalytic heads and nucleobase-interacting neck domains of the phylogenetically closely related Aquifex aeolicus A-adding enzyme by the corresponding domains of the T. maritima CCA-adding enzyme allowed the A-adding enzyme to add CCA in vivo and in vitro. However, the replacement of only the catalytic head domain did not allow the A-adding enzyme to add CCA, and the enzyme exhibited (A, C)-adding activity. We identified the region in the neck domain that prevents (A, C)-adding activity and defines the number of nucleotide incorporations and the specificity for correct CCA addition. We also identified the region in the head domain that defines the terminal A addition after CC addition. The results collectively suggest that, in the class II CCA-adding enzyme, the head and neck domains collaboratively and dynamically define the number of nucleotide additions and the specificity of nucleotide selection.

PubMed: 19745807
DOI: 10.1038/emboj.2009.260

Experimental method

X-RAY DIFFRACTION (2.801 Å)