1OU5

Crystal structure of human CCA-adding enzyme


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.4 Å
  • R-Value Free: 0.318 
  • R-Value Work: 0.278 

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


  • 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 tem ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
tRNA CCA-adding enzyme
A, B
448Homo sapiensGene Names: TRNT1
EC: 2.7.7.72
Find proteins for Q96Q11 (Homo sapiens)
Go to Gene View: TRNT1
Go to UniProtKB:  Q96Q11
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.4 Å
  • R-Value Free: 0.318 
  • R-Value Work: 0.278 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 102.520α = 90.00
b = 102.520β = 90.00
c = 206.658γ = 120.00
Software Package:
Software NamePurpose
SHARPphasing
CCP4data scaling
MOSFLMdata reduction
SCALAdata scaling
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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