1OU5

Crystal structure of human CCA-adding enzyme


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.40 Å
  • R-Value Free: 0.318 
  • R-Value Work: 0.278 
  • R-Value Observed: 0.282 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Crystal Structure of the Human CCA-adding Enzyme: Insights into Template-independent Polymerization

Augustin, M.A.Reichert, A.S.Betat, H.Huber, R.Moerl, M.Steegborn, C.

(2003) J Mol Biol 328: 985-994

  • DOI: 10.1016/s0022-2836(03)00381-4
  • Primary Citation of Related Structures:  
    1OU5

  • PubMed Abstract: 
  • 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 ...

    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.


    Organizational Affiliation

    Max-Planck-Institut für Biochemie, Abteilung Strukturforschung, Am Klopferspitz 18A, D-82152 Martinsried, Germany. augustin@biochem.mpg.de



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
tRNA CCA-adding enzymeA, B448Homo sapiensMutation(s): 0 
Gene Names: hMtCCATRNT1CGI-47
EC: 2.7.7.72
UniProt & NIH Common Fund Data Resources
Find proteins for Q96Q11 (Homo sapiens)
Explore Q96Q11 
Go to UniProtKB:  Q96Q11
PHAROS:  Q96Q11
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.40 Å
  • R-Value Free: 0.318 
  • R-Value Work: 0.278 
  • R-Value Observed: 0.282 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 102.52α = 90
b = 102.52β = 90
c = 206.658γ = 120
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
SHARPphasing
REFMACrefinement
CCP4data scaling

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-05-06
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Advisory, Refinement description