3FLO: Crystal Structure Of The Carboxyl-Terminal Domain Of Yeast Dna Polymerase Alpha In Complex With Its B Subunit

Eukaryotic DNA replication requires the coordinated activity of the multi-subunit DNA polymerases: Pol alpha, Pol delta and Pol epsilon. The conserved catalytic and regulatory B subunits associate in a constitutive heterodimer that represents the functional core of all three replicative polymerases. Here, we combine X-ray crystallography and electron microscopy (EM) to describe subunit interaction and 3D architecture of heterodimeric yeast Pol alpha. The crystal structure of the C-terminal domain (CTD) of the catalytic subunit bound to the B subunit illustrates a conserved mechanism of accessory factor recruitment by replicative polymerases. The EM reconstructions of Pol alpha reveal a bilobal shape with separate catalytic and regulatory modules. Docking of the B-CTD complex in the EM reconstruction shows that the B subunit is tethered to the polymerase domain through a structured but flexible linker. Our combined findings provide a structural template for the common functional architecture of the three major replicative DNA polymerases.
PDB ID: 3FLODownload
MMDB ID: 73155
PDB Deposition Date: 2008/12/19
Updated in MMDB: 2012/09
Experimental Method:
x-ray diffraction
Resolution: 2.5  Å
Source Organism:
Similar Structures:
Biological Unit for 3FLO: trimeric; determined by author
Molecular Components in 3FLO
Label Count Molecule
Proteins (3 molecules)
DNA Polymerase Alpha Subunit B(Gene symbol: POL12)
Molecule annotation
DNA Polymerase Alpha Catalytic Subunit a
Molecule annotation
DNA Polymerase Alpha Catalytic Subunit a(Gene symbol: POL1)
Molecule annotation
Chemicals (21 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB