1RA6: Poliovirus Polymerase Full Length Apo Structure

The active RNA-dependent RNA polymerase of poliovirus, 3Dpol, is generated by cleavage of the 3CDpro precursor protein, a protease that has no polymerase activity despite containing the entire polymerase domain. By intentionally disrupting a known and persistent crystal packing interaction, we have crystallized the poliovirus polymerase in a new space group and solved the complete structure of the protein at 2.0 A resolution. It shows that the N-terminus of fully processed 3Dpol is buried in a surface pocket where it makes hydrogen bonds that act to position Asp238 in the active site. Asp238 is an essential residue that selects for the 2' OH group of substrate rNTPs, as shown by a 2.35 A structure of a 3Dpol-GTP complex. Mutational, biochemical, and structural data further demonstrate that 3Dpol activity is exquisitely sensitive to mutations at the N-terminus. This sensitivity is the result of allosteric effects where the structure around the buried N-terminus directly affects the positioning of Asp238 in the active site.
PDB ID: 1RA6Download
MMDB ID: 28888
PDB Deposition Date: 2003/10/31
Updated in MMDB: 2004/11
Experimental Method:
x-ray diffraction
Resolution: 2  Å
Source Organism:
Similar Structures:
Biological Unit for 1RA6: monomeric; determined by author
Molecular Components in 1RA6
Label Count Molecule
Protein (1 molecule)
Genome Polyprotein
Molecule annotation
Chemicals (8 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB