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Figure 1

From: SJP-L-5 inhibits HIV-1 polypurine tract primed plus-strand DNA elongation, indicating viral DNA synthesis initiation at multiple sites under drug pressure

Figure 1

Different processes of reverse transcription in retroviruses. (a) Classical model of reverse transcription in retroviruses. (1) Reverse transcription is initiated by a tRNA primer at the PBS site near the 5′ end of the genome. (2) R′U5′ is translocated to the 3′ end of the genome and triggers the minus-DNA synthesis. This step is known as the first jump. (3) PPT, near the 3′ end of the genome, is used as a primer to initiate the plus-strand DNA synthesis. (4) PBS is used as a primer to form a circular DNA structure; this step is known as the second jump. (b) Modified model of reverse transcription in lentiviruses (i.e., HIV). HIV has an extra PPT site in the center of the genome, called cPPT. (3°) Both cPPT and PPT are used as primers to initiate the plus-strand DNA synthesis. (4°) The downstream plus-strand DNA is synthesized until the RTase reaches a strong-stop DNA site (U3-R-U5). (5°) Finally, the synthesis of the upstream plus-strand DNA stops at the CTS site near the center of the genome, and a discontinued plus-strand DNA is formed. Note that the actual proportions of the sequences have been altered in the diagram. Yellow line: viral plus-strand RNA; green line: viral minus-strand DNA; red line: viral plus-strand DNA. This figure was modified with permission from REF. 2© (2017) Microbiology Society.

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