Bivalent recognition of fatty acyl-CoA by a human integral membrane palmitoyltransferase.
Bivalent recognition of fatty acyl-CoA by a human integral membrane palmitoyltransferase.
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DOI：
10.1073/pnas.2022050119
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发表时间：
2022-02-15
影响因子：
11.1
通讯作者：
Banerjee A
中科院分区：
文献类型：
--
作者：
Lee CJ;Stix R;Rana MS;Shikwana F;Murphy RE;Ghirlando R;Faraldo-Gómez JD;Banerjee A
蛋白质棕榈酰化是最丰富的蛋白质修饰之一，长链脂肪酸通过硫酯键连接到半胱氨酸上。它在生长信号传导、突触受体的组织和离子通道功能的调节中发挥着至关重要的作用。然而，对于催化这种修饰的整合膜酶 DHHC 家族的分子机制仍然知之甚少。在这里，我们展示了人 DHHC20 与棕榈酰辅酶 A 的预催化复合物的结构。与随附的功能数据一起，该结构表明 DHHC 酶同时在脂肪酰基和 CoA 头基上对棕榈酰 CoA 进行二价识别对于催化化学的进行至关重要。 S-酰化，也称为棕榈酰化，是人类中最丰富的蛋白质脂化形式。这种可逆的翻译后修饰以数千种蛋白质为目标，由 DHHC 整合膜酶家族的 23 个成员催化。 DHHC 酶使用脂肪酰基辅酶 A 作为普遍存在的脂肪酰基供体，并在催化半胱氨酸处发生自酰化；该中间体随后将脂肪酰基转移到目标蛋白中的半胱氨酸上。蛋白质 S-酰化几乎与人类生理学的所有领域都有交叉，并且多种 DHHC 酶被认为是癌症等疾病的可能治疗靶点。这些努力将极大地受益于对这一关键酶促反应的分子基础的详细了解。在这里，我们将 X 射线晶体学与全原子分子动力学模拟相结合，阐明了人 DHHC20 与棕榈酰辅酶 A 复合物的预催化复合物的结构。由此产生的结构表明，脂肪酰链插入到蛋白质跨膜区域内的疏水口袋中，而 CoA 头基通过极性和离子相互作用被胞质结构域识别。生化实验证实了我们结构模型的预测。我们通过计算和实验分析表明，棕榈酰 CoA 作为二价配体，其中 DHHC 酶与脂肪酰基链和 CoA 头基的相互作用对于催化化学的进行非常重要。这种二价性解释了在生理条件下存在高浓度游离 CoA 的情况下，DHHC 酶如何有效地利用棕榈酰 CoA 作为自酰化的底物。
Protein palmitoylation is one of the most highly abundant protein modifications, through which long-chain fatty acids get attached to cysteines by a thioester linkage. It plays critically important roles in growth signaling, the organization of synaptic receptors, and the regulation of ion channel function. Yet the molecular mechanism of the DHHC family of integral membrane enzymes that catalyze this modification remains poorly understood. Here, we present the structure of a precatalytic complex of human DHHC20 with palmitoyl CoA. Together with the accompanying functional data, the structure shows how a bivalent recognition of palmitoyl CoA by the DHHC enzyme, simultaneously at both the fatty acyl group and the CoA headgroup, is essential for catalytic chemistry to proceed. S-acylation, also known as palmitoylation, is the most abundant form of protein lipidation in humans. This reversible posttranslational modification, which targets thousands of proteins, is catalyzed by 23 members of the DHHC family of integral membrane enzymes. DHHC enzymes use fatty acyl-CoA as the ubiquitous fatty acyl donor and become autoacylated at a catalytic cysteine; this intermediate subsequently transfers the fatty acyl group to a cysteine in the target protein. Protein S-acylation intersects with almost all areas of human physiology, and several DHHC enzymes are considered as possible therapeutic targets against diseases such as cancer. These efforts would greatly benefit from a detailed understanding of the molecular basis for this crucial enzymatic reaction. Here, we combine X-ray crystallography with all-atom molecular dynamics simulations to elucidate the structure of the precatalytic complex of human DHHC20 in complex with palmitoyl CoA. The resulting structure reveals that the fatty acyl chain inserts into a hydrophobic pocket within the transmembrane spanning region of the protein, whereas the CoA headgroup is recognized by the cytosolic domain through polar and ionic interactions. Biochemical experiments corroborate the predictions from our structural model. We show, using both computational and experimental analyses, that palmitoyl CoA acts as a bivalent ligand where the interaction of the DHHC enzyme with both the fatty acyl chain and the CoA headgroup is important for catalytic chemistry to proceed. This bivalency explains how, in the presence of high concentrations of free CoA under physiological conditions, DHHC enzymes can efficiently use palmitoyl CoA as a substrate for autoacylation.
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影响因子：
3.3
作者：
Klauda, Jeffery B.;Venable, Richard M.;Freites, J. Alfredo;O'Connor, Joseph W.;Tobias, Douglas J.;Mondragon-Ramirez, Carlos;Vorobyov, Igor;MacKerell, Alexander D., Jr.;Pastor, Richard W.
通讯作者：
Pastor, Richard W.
DOI：
10.1007/978-1-4939-9532-5_16
发表时间：
2019-01-01
期刊：
PROTEIN LIPIDATION: METHODS AND PROTOCOLS
影响因子：
--
作者：
Blanc, Mathieu;David, Fabrice P. A.;van der Goot, F. Gisou
通讯作者：
van der Goot, F. Gisou
影响因子：
4.8
作者：
Lobo, S;Greentree, WK;Deschenes, RJ
通讯作者：
Deschenes, RJ
影响因子：
14.8
作者：
通讯作者：
--
影响因子：
5.5
作者：
Best, Robert B.;Zhu, Xiao;Shim, Jihyun;Lopes, Pedro E. M.;Mittal, Jeetain;Feig, Michael;MacKerell, Alexander D., Jr.
通讯作者：
MacKerell, Alexander D., Jr.