EC Number   |
Natural Substrates  |
|---|
   3.5.4.B9 | 2'-deoxycytidine + H2O |
in ssDNA |
| 3.5.4.B9 | cytosine in single-stranded DNA + H2O |
the APOBEC3 enzymes are a double-edged sword that can catalyze deamination of cytosine in genomic DNA, which results in potential genomic instability due to the many mutagenic fates of uracil. The enzymes must be able to efficiently deaminate transiently available single-stranded DNA during reverse transcription, replication, or transcription. Specific biochemical characteristics promote deamination in each situation to increase enzyme efficiency through processivity, rapid enzyme cycling between substrates, or oligomerization state |
| 3.5.4.B9 | cytosine in single-stranded DNA + H2O |
the enzyme restricts the infectivity of viruses, such as HIV-1, by targeting CCC hotspots scattered through minus DNA strands, reverse-transcribed from genomic RNA |
| 3.5.4.B9 | cytosine in single-stranded viral DNA + H2O |
- |
| 3.5.4.B9 | cytosine in single-stranded viral DNA + H2O |
cytosine deamination occurs preferentially in CpC (5'GpG/CpC5') |
| 3.5.4.B9 | cytosine in single-stranded viral DNA + H2O |
in vitro, the enzyme has a preferred sequence motif of T/CCC and shows a 3'->5' like processivity |
| 3.5.4.B9 | cytosine in single-stranded viral DNA + H2O |
native enzyme demonstrates a preference for deamination of the C residue proximal to the 5'-ssDNA end in the 5'CCC motif and deaminates the two C residues processively |
| 3.5.4.B9 | cytosine in single-stranded viral DNA + H2O |
phage M13mp2 circular DNA containing a series of in-frame 5'-AAACCCAAA hot motifs embedded in lacZalpha reporter sequence located within a single-stranded gapped region of M13 double-stranded DNA. The third C in the 5'-AAACCCAAA motif is deaminated predominantly |
| 3.5.4.B9 | cytosine in single-stranded viral DNA + H2O |
the enzyme carries out processive cytosine deamination by randomly binding, sliding and jumping bidirectionally on single-stranded DNA. The deamination by the enzyme proceeds predominantly 3'->5', resulting in preferential deamination at the target located closer to the 5' end of substrate. The enzyme favors deamination at the 5'C residue in the hot-spot motif CCC |
| 3.5.4.B9 | cytosine in single-stranded viral DNA + H2O |
the enzyme strongly prefers cytosines in a run of C's usually targeting the last base in the run. The enzyme readily converts the third cytosine in CCC to uracil but does not convert the first or the second cytosine in the sequence at detectable levels |
