3PIE: Crystal Structure Of The 5'->3' Exoribonuclease Xrn1, E178q Mutant

The 5'-->3' exoribonucleases (XRNs) have important functions in transcription, RNA metabolism and RNA interference. The structure of Rat1 (also known as Xrn2) showed that the two highly conserved regions of XRNs form a single, large domain that defines the active site of the enzyme. Xrn1 has a 510-residue segment after the conserved regions that is required for activity but is absent from Rat1/Xrn2. Here we report the crystal structures of Kluyveromyces lactis Xrn1 (residues 1-1,245, E178Q mutant), alone and in complex with a Mn(2+) ion in the active site. The 510-residue segment contains four domains (D1-D4), located far from the active site. Our mutagenesis and biochemical studies show that their functional importance results from their ability to stabilize the conformation of the N-terminal segment of Xrn1. These domains might also constitute a platform that interacts with protein partners of Xrn1.
PDB ID: 3PIEDownload
MMDB ID: 88553
PDB Deposition Date: 2010/11/6
Updated in MMDB: 2017/08
Experimental Method:
x-ray diffraction
Resolution: 2.9  Å
Source Organism:
Similar Structures:
Biological Unit for 3PIE: monomeric; determined by author and by software (PISA)
Molecular Components in 3PIE
Label Count Molecule
Protein (1 molecule)
5'->3' Exoribonuclease (Xrn1)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB