Mechanism of leucine signaling of Thermus thermophilus

点击翻译按钮获取中文摘要

We revealed that glutamate dehydrogenase(GDH) from Thermus thermophilus formed hetero-hexameric structure consisted from homologous two subunits ; catalytic subunit(GdhB) and regulatory subunit(GdhB), and this complex was subject to allosteric activation by hydrophobic amino acids especially leucine. We succeeded to determine the crystal structure of GdhA/GdhB/Leu complex and revealed the allosteric mechanism of GDH. GDH2 from human(hGDH2) is also subject to allosteric activation by leucine and we found that important residues for binding of leucine were conserved in hGDH2. The mutational analyses of hGDH2 revealed that hGDH2 was also allosterically activated by leucine with a similar manner with GDH from T. thermophilus.We also performed comprehensive analysis of gene regulation by means of DNA microarray tecnique and suggested that leucine was a signal of global regulation in T. thermophilus.