1g5i

Publication Abstract from PubMed

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.

Crystal structure and deletion analysis show that the accessory subunit of mammalian DNA polymerase gamma, Pol gamma B, functions as a homodimer.,Carrodeguas JA, Theis K, Bogenhagen DF, Kisker C Mol Cell. 2001 Jan;7(1):43-54. PMID:11172710^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.