Mutational comparison of the single-domained APOBEC3C and double-domained APOBEC3F/G anti-retroviral cytidine deaminases provides insight into their DNA target site specificities.
Mutational comparison of the single-domained APOBEC3C and double-domained APOBEC3F/G anti-retroviral cytidine deaminases provides insight into their DNA target site specificities.
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DOI：
10.1093/nar/gki343
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发表时间：
2005
影响因子：
14.9
通讯作者：
Neuberger MS
中科院分区：
文献类型：
--
作者：
Langlois MA;Beale RC;Conticello SG;Neuberger MS
人类APOBEC3F和APOBEC3G是双结构域脱氨酶，可以分别针对T-C或C-C二核苷酸，催化HIV-1和MLV逆转录病毒DNA复制中间体中的dC→dU脱氨。HIV-1通过其vif基因产物拮抗它们的作用，该产物已被证明（至少在APOBEC3G的情况下）与脱氨酶的n端结构域相互作用，触发其降解。在这里，我们将APOBEC3F和APOBEC3G与APOBEC3C进行比较，APOBEC3C是一种单结构域脱氨基酶，也可以作用于HIV-1和MLV。我们发现，尽管APOBEC3C在一个结构域中包含了vif结合和胞苷脱氨酶活性所需的所有信息，但APOBEC3F和APOBEC3G的c端结构域赋予了它们胞苷脱氨的靶位特异性。我们利用APOBEC3C虽然与APOBEC3F的c端结构域高度同源，但表现出明显的靶位特异性（倾向于Y-C二核苷酸），以鉴定APOBEC3F中可能影响其靶位特异性的残基。我们发现这种特异性可以通过几个不同位置的单氨基酸取代而改变，这表明APOBEC3介导的脱氧胞苷脱胺对5 '侧核苷酸的强烈依赖对APOBEC3结构的相对细微变化很敏感。该方法可以分离出APOBEC3 DNA突变体，这些突变体表现出新的靶点偏好。
Human APOBEC3F and APOBEC3G are double-domained deaminases that can catalyze dC→dU deamination in HIV-1 and MLV retroviral DNA replication intermediates, targeting T–C or C–C dinucleotides, respectively. HIV-1 antagonizes their action through its vif gene product, which has been shown (at least in the case of APOBEC3G) to interact with the N-terminal domain of the deaminase, triggering its degradation. Here, we compare APOBEC3F and APOBEC3G to APOBEC3C, a single-domained deaminase that can also act on both HIV-1 and MLV. We find that whereas APOBEC3C contains all the information necessary for both Vif-binding and cytidine deaminase activity in a single domain, it is the C-terminal domain of APOBEC3F and APOBEC3G that confer their target site specificity for cytidine deamination. We have exploited the fact that APOBEC3C, whilst highly homologous to the C-terminal domain of APOBEC3F, exhibits a distinct target site specificity (preferring Y–C dinucleotides) in order to identify residues in APOBEC3F that might affect its target site specificity. We find that this specificity can be altered by single amino acid substitutions at several distinct positions, suggesting that the strong dependence of APOBEC3-mediated deoxycytidine deamination on the 5′-flanking nucleotide is sensitive to relatively subtle changes in the APOBEC3 structure. The approach has allowed the isolation of APOBEC3 DNA mutators that exhibit novel target site preferences.
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影响因子：
3.7
作者：
BORMAN, AM;QUILLENT, C;CLAVEL, F
通讯作者：
CLAVEL, F
影响因子：
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Cumbers, SJ;Williams, GT;Neuberger, MS
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通讯作者：
Neuberger, MS
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作者：
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