Figure 4.
Primer synthesis requires specific positions in the poly-T stretch. (A) Effect of poly-T stretch mutations on POLRMT primase activity. Reactions were performed as in Fig 2A and template sequences are listed in supplementary Table S1 online. Positions of the individual Ts are indicated in the schematic representation of OriL. (B) Human mtDNA nts 5,751 and 5,752 are critical for OriL-specific initiation of lagging-strand DNA synthesis. The reactions were performed as in Fig 2C. (C) A schematic picture summarizing the structural requirements of human OriL. The essential T at position 5,751 is indicated in red. MW, molecular weight; nts, nucleotides; WT, wild-type.