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Fig. 6 | BMC Molecular Biology

Fig. 6

From: The Dictyostelium discoideum homologue of Twinkle, Twm1, is a mitochondrial DNA helicase, an active primase and promotes mitochondrial DNA replication

Fig. 6

Helicase activity and substrate preference of D. discoideum Twm1. In vitro helicase activity of Twm1 was determined at 21 °C using various fluorescently labelled dsDNA templates (Additional file 3: Table S1B). Each DNA template was heated to 100 °C (H; first lane) and assayed using a no protein negative control (N; empty vector purification; second lane) in addition to Twm1 (T; third lane). Substrate (S) and final product (P) are indicated. Overhang polarities and FAM labels (red dots) of substrates are also indicated. a Helicase assay using strict dsDNA (FHA0) or open fork-like dsDNA (5′ and 3′ overhangs; FHAOF). b Determination of Twm1 directionality using open fork-like dsDNA with one duplex overhang (FHAOF5 or FHAOF3). c Overhang requirements of Twm1 were determined using dsDNA with a single ssDNA overhang (5′ or 3′; FHA5 or FHA3, respectively). Directionality of Twm1 was reconfirmed by using a duplex 3′ overhang (FHA3D)

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