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Table 4 Nucleotide composition of the HIV-1 RNA genome over time (19832009)

From: The biased nucleotide composition of the HIV genome: a constant factor in a highly variable virus

HIV-1 group/subtype Number of genomes analyseda Average nucleotide composition % 1983-1997b Range Number of full-length genomes analysed Average nucleotide composition % 1998-2009b Range
M, subtype Ac 24 A 36.5 35.8-36.9 38 A 36.6 36.3-36.9
   C 17.5 17.3-17.8   C 17.5 17.0-17.7
   G 23.8 23.3-24.4   G 23.8 23.4-24.2
   U 22.3 21.8-22.6   U 22.1 21.8-22.5
M, subtype Bd 16 A 36.7 36.5-37.0 25 A 36.7 36.3-37.0
   C 17.4 17.1-17.7   C 17.4 17.1-17.7
   G 23.7 23.5-24.0   G 23.7 23.4-24.1
   U 22.2 22.0-22.4   U 22.3 22.1-22.5
N e 2 A 35.7 35.6-35.8 6 A 36.1 36.0-36.4
   C 17.7 17.6-17.9   C 17.5 17.2-17.9
   G 24.2 24.1-24.3   G 23.9 23.9-24.1
   U 22.3 22.2-22.3   U 22.2 22.0-22,4
O d 4 A 35.4 35.0-35.8 3 A 35.3 34.8-36.1
   C 18.7 18.6-18.8   C 18.8 18.3-19.1
   G 23.7 23.5-24.2   G 23.8 23.3-24.1
   U 22.2 21.9-22.4   U 22.1 21.9-22.3
P f 0 NA NA 2 A 34.1 33.9-34.4
      C 18.4 18.3-18.5
      G 24.5 24.4-24.6
      U 22.4 22.2-22.6
  1. a Gag-pol-env only.
  2. b No significant differences in nucleotide composition were scored between groups over time (p>0.05, Student’s t-test).
  3. c A shorter sequence of HIV-1 subtype A was analysed (approx. 8600 nt), as not many full-length genomes were available.
  4. d Only genomes with ≤ 10 ambiguous nucleotides were used for the analysis.
  5. e Seven of eighth group N genomes contain ambiguous nucleotides (range 5–38).
  6. f Only two full-length genomes of group P viruses are available from the Los Alamos Database, which contain 54 and 66 ambiguous nucleotides, respectively.