Epizyme, Inc., 840 Memorial Drive, Cambridge, MA 02139, USA Genstruct Inc., One Alewife Center, Cambridge, MA 02140, USA.
Chem Biol Drug Des. 2011 Aug;78(2):199-210. doi: 10.1111/j.1747-0285.2011.01135.x. Epub 2011 Jun 16.
A survey of the human genome was performed to understand the constituency of protein methyltransferases (both protein arginine and lysine methyltransferases) and the relatedness of their catalytic domains. We identified 51 protein lysine methyltransferase proteins based on similarity to the canonical Drosophila Su(var)3-9, enhancer of zeste (E(z)), and trithorax (trx) domain. Disruptor of telomeric silencing-1-like, a known protein lysine methyltransferase, did not fit within the protein lysine methyltransferase family, but did group with the protein arginine methyltransferases, along with 44 other proteins, including the METTL and NOP2/Sun domain family proteins. We show that a representative METTL, METTL11A, demonstrates catalytic activity as a histone methyltransferase. We also solved the co-crystal structures of disruptor of telomeric silencing-1-like with S-adenosylmethionine and S-adenosylhomocysteine bound in its active site. The conformation of both ligands is virtually identical to that found in known protein arginine methyltransferases, METTL and NOP2/Sun domain family proteins and is distinct from that seen in the Drosophila Su(var)3-9, enhancer of zeste (E(z)), and trithorax (trx) domain protein lysine methyltransferases. We have developed biochemical assays for 11 members of the protein methyltransferase target class and have profiled the affinity of three ligands for these enzymes: the common methyl-donating substrate S-adenosylmethionine; the common reaction product S-adenosylhomocysteine; and the natural product sinefungin. The affinity of each of these ligands is mapped onto the family trees of the protein lysine methyltransferases and protein arginine methyltransferases to reveal patterns of ligand recognition by these enzymes.
为了了解蛋白质甲基转移酶（包括蛋白质精氨酸和赖氨酸甲基转移酶）的组成以及它们催化结构域的亲缘关系，我们对人类基因组进行了调查。我们基于与经典果蝇 Su(var)3-9、增强子 of zeste(E(z))和 trithorax(trx)结构域的相似性，鉴定了 51 种蛋白质赖氨酸甲基转移酶蛋白。已知的蛋白质赖氨酸甲基转移酶 Disruptor of telomeric silencing-1-like 不符合蛋白质赖氨酸甲基转移酶家族，但与蛋白质精氨酸甲基转移酶一起与 44 种其他蛋白质（包括 METTL 和 NOP2/Sun 结构域家族蛋白）一起分组。我们表明，代表性的 METTL，METTL11A，表现出作为组蛋白甲基转移酶的催化活性。我们还解决了 Disruptor of telomeric silencing-1-like 与 S-腺苷甲硫氨酸和 S-腺苷同型半胱氨酸结合在其活性位点的共晶结构。两种配体的构象与在已知的蛋白质精氨酸甲基转移酶、METTL 和 NOP2/Sun 结构域家族蛋白中发现的配体几乎相同，与在果蝇 Su(var)3-9、增强子 of zeste(E(z))和 trithorax(trx)结构域蛋白赖氨酸甲基转移酶中看到的配体不同。我们已经为蛋白质甲基转移酶靶类别的 11 个成员开发了生化测定法，并对三种配体与这些酶的亲和力进行了分析：常见的甲基供体 S-腺苷甲硫氨酸；常见的反应产物 S-腺苷同型半胱氨酸；和天然产物 sinefungin。这些配体的亲和力映射到蛋白质赖氨酸甲基转移酶和蛋白质精氨酸甲基转移酶的系统发育树上，以揭示这些酶对配体的识别模式。
