Janardan Neelanjana, Paul Anju, Harijan Rajesh K, Wierenga Rikkert K, Murthy M R N
Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560 012, India.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2011 Jul 1;67(Pt 7):817-20. doi: 10.1107/S1744309111019324. Epub 2011 Jun 30.
Thiolases are important in fatty-acid degradation and biosynthetic pathways. Analysis of the genomic sequence of Mycobacterium smegmatis suggests the presence of several putative thiolase genes. One of these genes appears to code for an SCP-x protein. Human SCP-x consists of an N-terminal domain (referred to as SCP2 thiolase) and a C-terminal domain (referred as sterol carrier protein 2). Here, the cloning, expression, purification and crystallization of this putative SCP-x protein from M. smegmatis are reported. The crystals diffracted X-rays to 2.5 Å resolution and belonged to the triclinic space group P1. Calculation of rotation functions using X-ray diffraction data suggests that the protein is likely to possess a hexameric oligomerization with 32 symmetry which has not been observed in the other six known classes of this enzyme.
硫解酶在脂肪酸降解和生物合成途径中起着重要作用。耻垢分枝杆菌基因组序列分析表明存在几个假定的硫解酶基因。其中一个基因似乎编码一种SCP-x蛋白。人类SCP-x由一个N端结构域（称为SCP2硫解酶）和一个C端结构域（称为固醇载体蛋白2）组成。本文报道了从耻垢分枝杆菌中克隆、表达、纯化和结晶这种假定的SCP-x蛋白的过程。这些晶体的X射线衍射分辨率达到2.5 Å，属于三斜晶系空间群P1。利用X射线衍射数据计算旋转函数表明，该蛋白可能具有32对称性的六聚体寡聚化结构，这在该酶的其他六个已知类别中尚未观察到。
