![Intergenic region (IR) of phage f1 single-stranded viral DNA (the plus strand), comprising three cis-acting elements: packaging signal, minus-strand origin, and plus-strand origin. The plus-strand origin is divided into functional domains A and B (only part of domain B is included). [A]–[E] indicate the secondary structure hairpins in the plus strand. Four-digit numbers indicate nucleotide positions in the f1 genome. Arrows point to the end of the pIV coding sequence (1), the transcription terminator (2), the initiation site of the minus-strand RNA primer (3), and the origin of plus-strand synthesis (4). Modified from Zinder and Horiuchi (1985) with permission from the American Society for Microbiology.](F6.large.jpg)
Intergenic region (IR) of phage f1 single-stranded viral DNA (the plus strand), comprising three cis-acting elements: packaging signal, minus-strand origin, and plus-strand origin. The plus-strand origin is divided into functional domains A and B (only part of domain B is included). [A]–[E] indicate the secondary structure hairpins in the plus strand. Four-digit numbers indicate nucleotide positions in the f1 genome. Arrows point to the end of the pIV coding sequence (1), the transcription terminator (2), the initiation site of the minus-strand RNA primer (3), and the origin of plus-strand synthesis (4). Modified from Zinder and Horiuchi (1985) with permission from the American Society for Microbiology.
