Fig. 3: Role of the SD Loop and Wedge Helix in DNA strand separation.
From: Structural basis for intrinsic strand displacement activity of mitochondrial DNA polymerase
A, B A close-up view of the strand displacement region of Mip1. The n + 1 base pair is visible in Structure I (A), while its space is occupied by the R265 residue in the Wedge helix in Structure II (B). C Sequence conservation of the Wedge and SD-loop regions of mitochondrial DNAPs from various species. Conserved residues are highlighted in yellow. The F849Y polymorphism in the SD loop of DNAPs of some yeast species is shown in magenta. D Primer-template constructs used in primer extension assays. E Primer extension assay performed using Wedge helix and SD-loop mutants with a primer-template construct containing either single-stranded or double-stranded downstream DNA. F Primer extension assay performed using DN847 and N847A mutants in the SD-loop, with a primer-template construct containing either single-stranded or double-stranded downstream DNA.
