Modeling of pathogenic variants of mitochondrial DNA polymerase: insight into the replication defects and implication for human disease.

•Residue K1191 in polymerases homologous to human DNA polymerase gamma is poised to interactswith the 3′ end of the primer.•Amino acid variants near residue K1191 favors exonucleolysis.•Our data suggest that multiple amino acids could be involved in the primer-stand stabilization.