2IKF

Terminal uridylyl transferase 4 from Trypanosoma brucei with bound UTP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.228 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

UTP-bound and Apo Structures of a Minimal RNA Uridylyltransferase.

Stagno, J.Aphasizheva, I.Rosengarth, A.Luecke, H.Aphasizhev, R.

(2007) J.Mol.Biol. 366: 882-899

  • DOI: 10.1016/j.jmb.2006.11.065
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • 3'-Uridylylation of RNA is emerging as a phylogenetically widespread phenomenon involved in processing events as diverse as uridine insertion/deletion RNA editing in mitochondria of trypanosomes and small nuclear RNA (snRNA) maturation in humans. Thi ...

    3'-Uridylylation of RNA is emerging as a phylogenetically widespread phenomenon involved in processing events as diverse as uridine insertion/deletion RNA editing in mitochondria of trypanosomes and small nuclear RNA (snRNA) maturation in humans. This reaction is catalyzed by terminal uridylyltransferases (TUTases), which are template-independent RNA nucleotidyltransferases that specifically recognize UTP and belong to a large enzyme superfamily typified by DNA polymerase beta. Multiple TUTases, recently identified in trypanosomes, as well as a U6 snRNA-specific TUTase enzyme in humans, are highly divergent at the protein sequence level. However, they all possess conserved catalytic and UTP recognition domains, often accompanied by various auxiliary modules present at the termini or between conserved domains. Here we report identification, structural and biochemical analyses of a novel trypanosomal TUTase, TbTUT4, which represents a minimal catalytically active RNA uridylyltransferase. The TbTUT4 consists of only two domains that define the catalytic center at the bottom of the nucleoside triphosphate and RNA substrate binding cleft. The 2.0 Angstroms crystal structure reveals two significantly different conformations of this TUTase: one molecule is in a relatively open apo conformation, whereas the other displays a more compact TUTase-UTP complex. A single nucleoside triphosphate is bound in the active site by a complex network of interactions between amino acid residues, a magnesium ion and highly ordered water molecules with the UTP's base, ribose and phosphate moieties. The structure-guided mutagenesis and cross-linking studies define the amino acids essential for catalysis, uracil base recognition, ribose binding and phosphate coordination by uridylyltransferases. In addition, the cluster of positively charged residues involved in RNA binding is identified. We also report a 2.4 Angstroms crystal structure of TbTUT4 with the bound 2' deoxyribonucleoside, which provides the structural basis of the enzyme's preference toward ribonucleotides.


    Organizational Affiliation

    Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
RNA uridylyl transferase
A, B
353Trypanosoma brucei brucei (strain 927/4 GUTat10.1)Mutation(s): 0 
Find proteins for Q381M1 (Trypanosoma brucei brucei (strain 927/4 GUTat10.1))
Go to UniProtKB:  Q381M1
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
UTP
Query on UTP

Download SDF File 
Download CCD File 
A
URIDINE 5'-TRIPHOSPHATE
C9 H15 N2 O15 P3
PGAVKCOVUIYSFO-XVFCMESISA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.228 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 78.773α = 90.00
b = 41.525β = 94.94
c = 103.792γ = 90.00
Software Package:
Software NamePurpose
CCP4data scaling
PHASERphasing
d*TREKdata reduction
CNSrefinement
PDB_EXTRACTdata extraction
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2006-10-02 
  • Released Date: 2007-02-20 
  • Deposition Author(s): Luecke, H., Stagno, J.

Revision History 

  • Version 1.0: 2007-02-20
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-18
    Type: Refinement description