2P51: Crystal Structure Of The S. Pombe Pop2p Deadenylation Subunit

Deadenylation is the first and probably also rate-limiting step of controlled mRNA decay in eukaryotes and therefore central for the overall rate of gene expression. In yeast, the process is maintained by the mega-Dalton Ccr4-Not complex, of which both the Ccr4p and Pop2p subunits are 3'-5' exonucleases potentially responsible for the deadenylation reaction. Here, we present the crystal structure of the Pop2p subunit from Schizosaccharomyces pombe determined to 1.4 A resolution and show that the enzyme is a competent ribonuclease with a tunable specificity towards poly-A. In contrast to S. cerevisiae Pop2p, the S. pombe enzyme contains a fully conserved DEDDh active site, and the high resolution allows for a detailed analysis of its configuration, including divalent metal ion binding. Functional data further indicates that the identity of the ions in the active site can modulate both activity and specificity of the enzyme, and finally structural superposition of single nucleotides and poly-A oligonucleotides provide insight into the catalytic cycle of the protein.
PDB ID: 2P51Download
MMDB ID: 46502
PDB Deposition Date: 2007/3/14
Updated in MMDB: 2017/10
Experimental Method:
x-ray diffraction
Resolution: 1.4  Å
Source Organism:
Similar Structures:
Biological Unit for 2P51: monomeric; determined by author
Molecular Components in 2P51
Label Count Molecule
Protein (1 molecule)
Spcc18.06c Protein(Gene symbol: caf1)
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

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