Fig. 4: Structural alignment of the wedge of Pif1 orthologs.
From: Eukaryotic Pif1 helicase unwinds G-quadruplex and dsDNA using a conserved wedge
a Structural alignment of the wedge regions of Pif1 from Saccharomyces cerevisiae, Homo sapiens, Bacteroides sp., and Thermus oshimai. The cartoon representations show the superposed wedge regions of ScPif1 (limon), HsPif1(gray) (PDB code: 5FHH), BaPif1(purple) (PDB code: 5FHE) and ToPif1(red) (PDB code: 7OAR). The wedge region in prokaryotic Pif1 helicases has an extended region followed by an α-helix while the wedge in eukaryotic Pif1 helicases contains two α-helices connected by a short loop. The key positively charged residues in the wedge regions, R324 in ScPif1, R290 in HsPif1, and K87 in BaPif1 are shown in sticks. b Structure-based sequence alignment of the wedge regions of Pif1 orthologs.
