Figure 4: DNA strand-displacement and ligation activity of POLγ mutants. | Nature Communications

Figure 4: DNA strand-displacement and ligation activity of POLγ mutants.

From: The exonuclease activity of DNA polymerase γ is required for ligation during mitochondrial DNA replication

Figure 4

(a) Time course of strand displacement by purified recombinant WT and mutant POLγ proteins. The reactions were performed as depicted in Fig. 1a. Arrows: solid lines indicate gap filling; broken lines indicate strand displacement. Lanes are numbered 1–54. (b) Strand-displacement reactions as above resolved on a sequencing gel. The failure by G303R, L304R and S305R to reverse to the nick position at the 10 min time point is evident (arrowhead at 50 nts). The sizes of an oligonucleotide molecular marker are indicated to the left. (c) Quantification of ligation efficiencies (ligation product formed as percentage of substrate) of the different POLγ proteins relative to WT. The ligation assay and quantification was performed as in Fig. 2c–e. Mean values±s.e.m., WT was set to 100%, asterisks represent significant differences compared with WT (n=3; *P≤0.05, **P≤0.01, ***P≤0.001; one way analysis of variance).

Back to article page