Insights into the motif preference of APOBEC3 enzymes.
We used a multivariate data analysis approach to identify motifs associated with HIV hypermutation by different APOBEC3 enzymes. The analysis showed that APOBEC3G targets G mainly within GG, TG, TGG, GGG, TGGG and also GGGT. The G nucleotides flanked by a C at the 3' end (in +1 and +2 positions) were indicated as disfavoured targets by APOBEC3G. The G nucleotides within GGGG were found to be targeted at a frequency much less than what is expected. We found that the infrequent G-to-A mutation within GGGG is not limited to the inaccessibility, to APOBEC3, of poly Gs in the central and 3'polypurine tracts (PPTs) which remain double stranded during the HIV reverse transcription. GGGG motifs outside the PPTs were also disfavoured. The motifs GGAG and GAGG were also found to be disfavoured targets for APOBEC3. The motif-dependent mutation of G within the HIV genome by members of the APOBEC3 family other than APOBEC3G was limited to GA→AA changes. The results did not show evidence of other types of context dependent G-to-A changes in the HIV genome.
Complex Systems in Biology Group, Centre for Vascular Research, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
Diako
D
Ebrahimi
Complex Systems in Biology Group, Centre for Vascular Research, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
Hamid
H
Alinejad-Rokny
Complex Systems in Biology Group, Centre for Vascular Research, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
Miles P
MP
Davenport
D000071480:APOBEC-3G Deaminase; D018899:CpG Islands; D003564:Cytidine Deaminase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004279:DNA, Viral / Q000737:chemistry*; D016679:Genome, Viral; D015497:HIV-1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D017354:Point Mutation; D013379:Substrate Specificity
D004279:DNA, Viral; D000071480:APOBEC-3G Deaminase; C464924:APOBEC3G protein, human; D003564:Cytidine Deaminase