CRYSTALLOGRAPHIC STUDIES OF TERNARY COMPLEXES OF NMT1P

NMT1P三元配合物的晶体学研究

• 批准号: 6119543
• 负责人: GABRIEL WAKSMAN
• 金额: --
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-01 至 2000-04-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6119543
• 关键词: biomaterials; proteins; structural biology

Nmtlp is an enzyme of 455 amino acids that catalyzes the transfer of myristate to the N-terminal glycine of cellular eukaryotic proteins. Myristoylation is used to mediate potentially reversible protein-protein and protein-membrane interactions that are necessary for the biological function of myristoylated proteins. N-myristoylation is an essential cellular process and proteins that become myrisloylated include protein tyrosine kinases, phosphatases, heterotrimeric G-proteins, as well as structural and non-structural proteins of numerous viruses including HIV. Nmts from pathogenic fungi are also important targets for design of antifungal drugs. We have recently solved the structure of Nmtlp in a ternary complex with a myristoylCoA and a peptide substrate analog using MAD data collected at BNL (Bhatnagar et al. (1998), Nature Structural Biology, in press). This ternary complex structure reveals the structural features that define the enzyme's substrate specificities and regulate the ordered binding and release of substrates and products. This structure also suggests a novel catalytic mechanism which involves deprotonation of the N-terminal ammonium of a peptide substrate by the enzyme's C-terminal backbone carboxylate. We now have crystals of the same enzyme bound to the same myristoylCoA analog but with one natural peptide substrate (crystal n 1). In addition, another ternary complex with a bound natural peptide inhibitor has been generated (crystal n 2). Solving the structure of a complex with a natural peptide will further delineate the novel mechanism of catalysis by this enzyme which we proposed based on the initial structure. Crystal n 1 and n 2 diffracted to 3.5 E and 3.3 E, respectively, were both in space group P3121 with unit cell dimensions a = b = 103 E, c = 108 E. Given the poor resolution of the data, synchrotron radiation would clearly be advantageous to this project.

Nmtlp 是一种由 455 个氨基酸组成的酶，可催化转移 肉豆蔻酸与细胞真核生物的 N 末端甘氨酸的连接 蛋白质。 肉豆蔻酰化用于介导潜在的可逆性 必要的蛋白质-蛋白质和蛋白质-膜相互作用 用于肉豆蔻酰化蛋白质的生物学功能。 N-肉豆蔻酰化是一个重要的细胞过程和蛋白质 被豆蔻酰化包括蛋白酪氨酸激酶、磷酸酶、 异三聚体 G 蛋白，以及结构和非结构 包括 HIV 在内的多种病毒的蛋白质。 致病性 Nmts 真菌也是抗真菌药物设计的重要靶点。 我们 最近解决了三元配合物中 Nmtlp 的结构 使用收集的 MAD 数据的肉豆蔻酰辅酶 A 和肽底物类似物 BNL（Bhatnagar 等人（1998），《自然结构生物学》，出版中）。 这种三元复杂结构揭示了以下结构特征： 定义酶的底物特异性并调节有序 底物和产物的结合和释放。 这个结构也 提出了一种新的催化机制，其中涉及去质子化 通过酶的作用，肽底物的 N 末端铵 C-末端主链羧酸酯。 我们现在有相同的晶体 酶与相同的肉豆蔻酰辅酶A类似物结合，但具有一种天然的 肽底物（晶体 n 1）。 此外，还有另一种三元配合物 与结合的天然肽抑制剂已经产生（晶体n 2）。 用天然肽解析复合物的结构将 进一步描述该酶催化的新机制 这是我们根据初始结构提出的。 晶体 n 1 和 n 2 分别衍射至 3.5 E 和 3.3 E，均属于空间群 P3121 的晶胞尺寸 a = b = 103 E, c = 108 E。 数据分辨率差，同步加速器辐射显然会 对本项目有利。