Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Crystal structure of the human CCA-adding enzyme: Insights into template-independent polymerization

Augustin, Martin A, Reichert, Andreas S, Betat, Heike, Huber, Robert, Mörl, Mario and Steegborn, Clemens 2003. Crystal structure of the human CCA-adding enzyme: Insights into template-independent polymerization. Journal of Molecular Biology 328 (5) , pp. 985-994. 10.1016/S0022-2836(03)00381-4

Full text not available from this repository.


All tRNA molecules carry the invariant sequence CCA at their 3′-terminus for amino acid attachment. The post-transcriptional addition of CCA is carried out by ATP(CTP):tRNA nucleotidyltransferase, also called CCase. This enzyme catalyses a unique template-independent but sequence-specific nucleotide polymerization reaction. In order to reveal the molecular mechanism of this activity, we solved the crystal structure of human CCase by single isomorphous replacement. The structure reveals a four domain architecture with a cluster of conserved residues forming a positively charged cleft between the first two domains. Structural homology of the N-terminal CCase domain to other nucleotidyltransferases could be exploited for modeling a tRNA–substrate complex. The model places the tRNA 3′-end into the N-terminal nucleotidyltransferase site, close to a patch of conserved residues that provide the binding sites for CTP and ATP. Based on our results, we introduce a corkscrew model for CCA addition that includes a fixed active site and a traveling tRNA-binding region formed by flexible parts of the protein.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Biosciences
Publisher: Elsevier
ISSN: 0022-2836
Last Modified: 24 Jun 2017 11:00

Citation Data

Cited 51 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item