1W9H

The Structure of a Piwi protein from Archaeoglobus fulgidus.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.192 
  • R-Value Observed: 0.194 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Crystal Structure of a Piwi Protein Suggests Mechanisms for Sirna Recognition and Slicer Activity

Parker, J.S.Roe, S.M.Barford, D.

(2004) EMBO J 23: 4727

  • DOI: https://doi.org/10.1038/sj.emboj.7600488
  • Primary Citation of Related Structures:  
    1W9H

  • PubMed Abstract: 

    RNA silencing regulates gene expression through mRNA degradation, translation repression and chromatin remodelling. The fundamental engines of RNA silencing are RISC and RITS complexes, whose common components are 21-25 nt RNA and an Argonaute protein containing a PIWI domain of unknown function. The crystal structure of an archaeal Piwi protein (AfPiwi) is organised into two domains, one resembling the sugar-binding portion of the lac repressor and another with similarity to RNase H. Invariant residues and a coordinated metal ion lie in a pocket that surrounds the conserved C-terminus of the protein, defining a key functional region in the PIWI domain. Furthermore, two Asp residues, conserved in the majority of Argonaute sequences, align spatially with the catalytic Asp residues of RNase H-like catalytic sites, suggesting that in eukaryotic Argonaute proteins the RNase H-like domain may possess nuclease activity. The conserved region around the C-terminus of the PIWI domain, which is required for small interfering RNA (siRNA) binding to AfPiwi, may function as the receptor site for the obligatory 5' phosphate of siRNAs, thereby specifying the cleavage position of the target mRNA.


  • Organizational Affiliation

    Section of Structural Biology, The Institute of Cancer Research, Chester Beatty Laboratories, London, UK.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
HYPOTHETICAL PROTEIN AF1318427Archaeoglobus fulgidusMutation(s): 0 
UniProt
Find proteins for O28951 (Archaeoglobus fulgidus (strain ATCC 49558 / DSM 4304 / JCM 9628 / NBRC 100126 / VC-16))
Explore O28951 
Go to UniProtKB:  O28951
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO28951
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CD
Query on CD

Download Ideal Coordinates CCD File 
B [auth A],
C [auth A]
CADMIUM ION
Cd
WLZRMCYVCSSEQC-UHFFFAOYSA-N
NI
Query on NI

Download Ideal Coordinates CCD File 
D [auth A],
E [auth A],
F [auth A],
G [auth A],
H [auth A]
NICKEL (II) ION
Ni
VEQPNABPJHWNSG-UHFFFAOYSA-N
CL
Query on CL

Download Ideal Coordinates CCD File 
I [auth A],
J [auth A],
K [auth A],
L [auth A]
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.192 
  • R-Value Observed: 0.194 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 69.09α = 90
b = 137.863β = 90
c = 51.663γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
SnBphasing
SHARPphasing
REFMACrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-01-13
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-07-05
    Changes: Refinement description
  • Version 1.4: 2024-05-08
    Changes: Data collection, Database references, Derived calculations, Other