查看文章

A gene encoding 544 amino acids for a subunit of group II chaperonin (thermosome) was cloned from a thermophilic methanogen, Methanococcus thermolithotrophicus. The deduced amino acid sequence showed 66.5, 56.1, and 20.1% similarities to those of Methanopyrus kandleri and Thermoplasma acidophilum and group I chaperonin of Escherichia coli, respectively. We call this chaperonin MTTS (M. thermolithotrophicus thermosome). The MTTS gene was expressed in E. coli. The purified recombinant MTTS seemed to be monomeric on gel filtration in the absence of Mg²⁺ and ATP. The monomer assembled to an oligomer (complex) in the presence of 50 mm MgCl₂, 0.25 mm ATP, and 0.3m (NH₄)₂SO₄. It was eluted immediately before the elution volume of E. coliGroEL tetradecamer on gel filtration with a TSKgel G3000SWXL column. This reconstructed MTTS complex showed the cylindrical structure with two …