1G5I

CRYSTAL STRUCTURE OF THE ACCESSORY SUBUNIT OF MURINE MITOCHONDRIAL POLYMERASE GAMMA

Summary for 1G5I

• Entry DOI: 10.2210/pdb1g5i/pdb
• Related: 1G5H
• Descriptor: MITOCHONDRIAL DNA POLYMERASE ACCESSORY SUBUNIT, SODIUM ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: intermolecular four helix bundle, dna binding protein
• Biological source: Mus musculus (house mouse)
• Total number of polymer chains: 4
• Total formula weight: 204495.80

Authors

Carrodeguas, J.A.,Theis, K.,Bogenhagen, D.F.,Kisker, C. (deposition date: 2000-11-01, release date: 2001-03-14, Last modification date: 2023-08-09)

Primary citation

Carrodeguas, J.A.,Theis, K.,Bogenhagen, D.F.,Kisker, C.
Crystal structure and deletion analysis show that the accessory subunit of mammalian DNA polymerase gamma, Pol gamma B, functions as a homodimer.
Mol.Cell, 7:43-54, 2001

PubMed Abstract: Polymerase gamma, which replicates and repairs mitochondrial DNA, requires the Pol gamma B subunit for processivity. We determined the crystal structure of mouse Pol gamma B, a core component of the mitochondrial replication machinery. Pol gamma B shows high similarity to glycyl-tRNA synthetase and dimerizes through an unusual intermolecular four-helix bundle. A human Pol gamma B mutant lacking the four-helix bundle failed to dimerize in solution or to stimulate the catalytic subunit Pol gamma A, but retained the ability to bind with Pol gamma A to a primer-template construct, indicating that the functional holoenzyme contains two Pol gamma B molecules. Other mutants retained stimulatory activity but lost the ability to bind folded ssDNA. These results suggest that the Pol gamma B dimer contains distinct sites for Pol gamma A binding, dimerization, and DNA binding.

PubMed: 11172710
DOI: 10.1016/S1097-2765(01)00153-8

Experimental method

X-RAY DIFFRACTION (2.3 Å)