The accessory subunit of Xenopus laevis mitochondrial DNA polymerase gamma increases processivity of the catalytic subunit of human DNA polymerase gamma and is related to class II aminoacyl-tRNA synthetases.

ABSTRACT: Peptide sequences obtained from the accessory subunit of Xenopus laevis mitochondrial DNA (mtDNA) polymerase gamma (pol gamma) were used to clone the cDNA encoding this protein. Amino-terminal sequencing of the mitochondrial protein indicated the presence of a 44-amino-acid mitochondrial targeting sequence, leaving a predicted mature protein with 419 amino acids and a molecular mass of 47.3 kDa. This protein is associated with the larger, catalytic subunit in preparations of active mtDNA polymerase. The small subunit exhibits homology to its human, mouse, and Drosophila counterparts. Interestingly, significant homology to glycyl-tRNA synthetases from prokaryotic organisms reveals a likely evolutionary relationship. Since attempts to produce an enzymatically active recombinant catalytic sub

SUBMITTER: Carrodeguas JA 

PROVIDER: S-EPMC104363 | biostudies-literature | 1999 Jun

REPOSITORIES: biostudies-literature