A unique family of Mrr-like modification-dependent restriction endonucleases.
A unique family of Mrr-like modification-dependent restriction endonucleases.
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DOI：
10.1093/nar/gkq327
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发表时间：
2010-09
影响因子：
14.9
通讯作者：
Roberts RJ
中科院分区：
文献类型：
--
作者：
Zheng Y;Cohen-Karni D;Xu D;Chin HG;Wilson G;Pradhan S;Roberts RJ
微生物基因组中同源基因Mrr超家族在体内限制修饰的DNA。然而，它们在体外的生物化学特性仍然不清楚。在这里，我们报告的实验表征MspJI，大肠杆菌的MRR的远程同源物，并显示它是一种DNA修饰依赖性限制性内切酶。我们的研究结果表明，MspJI识别mCNNR（R = G/A）位点，并在距离3′侧修饰的胞嘧啶固定距离（N12/N16）（或距离R的N9/N13）处切割DNA。除了5-甲基胞嘧啶，MspJI还识别5-羟甲基胞嘧啶，但被5-葡糖基羟甲基胞嘧啶阻断。MspJI的其他几个密切的同源物显示类似的修饰依赖性核酸内切酶活性，并显示与MspJI不同的底物偏好。这些修饰依赖性酶的一个独特特征是它们能够提取基因组DNA上含有修饰位点的小DNA片段，例如对称甲基化CG位点周围的约32 bp和甲基化CNG位点周围的约31 bp。消化的片段可以直接选择用于高通量测序以定位基因组DNA上的修饰的位置。MspJI酶家族具有不同的识别特异性和切割特性，为许多未来的方法提供了基础，以解码不同生物体的表观基因组。
Mrr superfamily of homologous genes in microbial genomes restricts modified DNA in vivo. However, their biochemical properties in vitro have remained obscure. Here, we report the experimental characterization of MspJI, a remote homolog of Escherichia coli’s Mrr and show it is a DNA modification-dependent restriction endonuclease. Our results suggest MspJI recognizes mCNNR (R = G/A) sites and cleaves DNA at fixed distances (N12/N16) away from the modified cytosine at the 3′ side (or N9/N13 from R). Besides 5-methylcytosine, MspJI also recognizes 5-hydroxymethylcytosine but is blocked by 5-glucosylhydroxymethylcytosine. Several other close homologs of MspJI show similar modification-dependent endonuclease activity and display substrate preferences different from MspJI. A unique feature of these modification-dependent enzymes is that they are able to extract small DNA fragments containing modified sites on genomic DNA, for example ∼32 bp around symmetrically methylated CG sites and ∼31 bp around methylated CNG sites. The digested fragments can be directly selected for high-throughput sequencing to map the location of the modification on the genomic DNA. The MspJI enzyme family, with their different recognition specificities and cleavage properties, provides a basis on which many future methods can build to decode the epigenomes of different organisms.
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影响因子：
14.9
作者：
Pei J;Kim BH;Tang M;Grishin NV
通讯作者：
Grishin NV
影响因子：
1.6
作者：
Mulligan EA;Dunn JJ
通讯作者：
Dunn JJ
影响因子：
3.2
作者：
WAITEREES, PA;KEATING, CJ;BENNER, JS
通讯作者：
BENNER, JS
影响因子：
14.9
作者：
Roberts RJ;Vincze T;Posfai J;Macelis D
通讯作者：
Macelis D
DOI：
10.1126/science.1170116
发表时间：
2009-05-15
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Tahiliani M;Koh KP;Shen Y;Pastor WA;Bandukwala H;Brudno Y;Agarwal S;Iyer LM;Liu DR;Aravind L;Rao A
通讯作者：
Rao A