1ou5
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1ou5.jpg|left|200px]] | [[Image:1ou5.jpg|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1ou5", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | + | or leave the SCENE parameter empty for the default display. | |
| - | + | --> | |
| - | + | {{STRUCTURE_1ou5| PDB=1ou5 | SCENE= }} | |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''Crystal structure of human CCA-adding enzyme''' | '''Crystal structure of human CCA-adding enzyme''' | ||
| Line 31: | Line 28: | ||
[[Category: Reichert, A S.]] | [[Category: Reichert, A S.]] | ||
[[Category: Steegborn, C.]] | [[Category: Steegborn, C.]] | ||
| - | [[Category: | + | [[Category: Nucleotidyltransferase]] |
| - | [[Category: | + | [[Category: Polymerase]] |
| - | [[Category: | + | [[Category: Trna]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 04:17:04 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 01:17, 3 May 2008
Crystal structure of human CCA-adding enzyme
Overview
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.
About this Structure
1OU5 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystal structure of the human CCA-adding enzyme: insights into template-independent polymerization., Augustin MA, Reichert AS, Betat H, Huber R, Morl M, Steegborn C, J Mol Biol. 2003 May 16;328(5):985-94. PMID:12729736 Page seeded by OCA on Sat May 3 04:17:04 2008
