Crystal structure of uncleaved L-aspartate-α-decarboxylase from Mycobacterium tuberculosis
Crystal structure of uncleaved L-aspartate-α-decarboxylase from Mycobacterium tuberculosis
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DOI：
10.1002/prot.21126
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发表时间：
2006-12-01
影响因子：
2.9
通讯作者：
Swaminathan, Kunchithapadam
中科院分区：
文献类型：
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作者：
Gopalan, Gayathri;Chopra, Sidharth;Swaminathan, Kunchithapadam
l-天冬氨酸- α -脱羧酶（ADC）是泛酸生物合成途径中重要的调节酶，属于一类自裂性和丙酮酰依赖的氨基酸脱羧酶。采用cDNA分析、抗ADC多克隆抗体全细胞裂解液免疫印迹和免疫电镜检测ADC在结核分枝杆菌（Mtb）中的表达水平。重组结核分枝杆菌（Mycobacterium tuberculosis, MtbADC） ADC前酶在大肠杆菌中过表达，以2.99 A的分辨率测定其蛋白结构。蛋白质折叠成双psi桶状结构。两个四聚体的亚基（不对称单元中有8个ADC分子）形成伪四重旋转对称，类似于大肠杆菌ADC前酶结构。由于泛酸盐是在微生物、植物和真菌中合成的，而不是在动物中合成的，因此阐明Mtb ADC的结构对基于结构的药物开发具有重要意义。
L-aspartate-alpha-decarboxylase (ADC) is a critical regulatory enzyme in the pantothenate biosynthetic pathway and belongs to a small class of self-cleaving and pyruvoyl-dependent amino acid decarboxylases. The expression level of ADC in Mycobacterium tuberculosis (Mtb) was confirmed by cDNA analysis, immunoblotting with an anti-ADC polyclonal antibody using whole cell lysate and immuno-electron microscopy. The recombinant ADC proenzyme from Mycobacterium tuberculosis (MtbADC) was overexpressed in E. coli and the protein structure was determined at 2.99 A resolution. The proteins fold into the double-psi beta-barrel structure. The subunits of the two tetramers (there are eight ADC molecules in the asymmetric unit) form pseudo fourfold rotational symmetry, similar to the E. coli ADC proenzyme structure. As pantothenate is synthesized in microorganisms, plants, and fungi but not in animals, structure elucidation of Mtb ADC is of substantial interest for structure-based drug development.