Importance of Ile71 in β-actin on histidine methyltransferase SETD3 catalysis
Importance of Ile71 in β-actin on histidine methyltransferase SETD3 catalysis
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DOI：
10.1039/d1ob02430b
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发表时间：
2022-02-02
影响因子：
3.2
通讯作者：
Mecinovic, Jasmin
中科院分区：
文献类型：
--
作者：
Bilgin, Nurgul;Moesgaard, Laust;Mecinovic, Jasmin
β-肌动蛋白中His 73的SETD 3-催化的N-3-甲基化在后生动物细胞中肌动蛋白丝的稳定中起关键作用。SETD 3的过表达和/或失调与几种人类病理学相关，包括癌症。在这里，我们研究了β-肌动蛋白中Ile 71残基对人SETD 3催化的作用。用其天然和非天然模拟物取代β-肌动蛋白肽中的Ile 71揭示了“二级”Ile 71结合口袋调节β-肌动蛋白的底物效率。我们的酶促工作表明，人SETD 3可以容纳结构多样的疏水侧链在其Ile 71结合口袋，提供明确的限制的大小和形状的Ile类似物。水热力学计算表明，Ile 71口袋被高能量水分子占据，这些水分子在Ile 71结合时释放，有利于SETD 3-β A复合物的形成。这项工作强调了疏水性Ile 71结合位点在SETD 3催化中起着至关重要的作用，有助于设计和开发针对SETD 3的化学探针。
SETD3-catalysed N-3-methylation of His73 in beta-actin plays a key role in stabilisation of actin filaments in the metazoan cells. Overexpression and/or dysregulation of SETD3 is associated with several human pathologies, including cancer. Here, we examined the role of the Ile71 residue in beta-actin on human SETD3 catalysis. Substitution of Ile71 in beta-actin peptides by its natural and unnatural mimics reveals that the 'secondary' Ile71 binding pocket modulates the substrate efficiency of beta-actin. Our enzymatic work demonstrates that human SETD3 can accommodate structurally diverse hydrophobic side chains in its Ile71 binding pocket, providing clear limits of the size and shape of Ile analogues. Water thermodynamics calculations reveal that the Ile71 pocket is occupied by high-energy water molecules, that are released upon the Ile71 binding, contributing favourably to the SETD3-beta A complex formation. The work highlights that the hydrophobic Ile71 binding site plays an essential role in SETD3 catalysis, contributing to an ongoing effort in the design and development of chemical probes targeting SETD3.