Identification and mapping of post-transcriptional modifications on the HIV-1 antisense transcript Ast in human cells

Putative secondary structure of Ast RNA predicted by using RNA Fold Web Server. (A) Overall secondary structure of Ast RNA, from nucleotides 1 through 2574. The color scale represents the probability of base pairing from 0 to 1. (B) Ast RNA sequence from Region I (nucleotides 1–620), with modification Am at position 173. (C) Ast RNA sequence from Region II (nucleotides 621–1284), with modifications Gm (positions 708 and 943), inosine (position 1027), Cm/m⁵C (position 1090), and ψ (position 1135). (D) Ast RNA sequence from Region III (nucleotides 1285–2574), with Gm (position 1554), Um/m³U (position 1636), m⁵C (position 1840), ψ (position 2238), and Am (position 2541).