Waldmann T, Lupas A, Kellermann J, Peters J, Baumeister W
Max-Planck-Institut für Biochemie, Martinsried, Germany.
Biol Chem Hoppe Seyler. 1995 Feb;376(2):119-26. doi: 10.1515/bchm3.1995.376.2.119.
The thermosome, a chaperonin from the archaebacterium Thermoplasma acidophilum, consists of two subunits (M(r) 58,000 and 60,000) which assemble into a cylindrical complex of pseudo eight-fold rotational symmetry. The sequences of the two subunits are approximately 60% identical to each other and to TF55 from Sulfolobus shibatae, and are 30-40% identical to the subunits of the TCP1 containing ring complex (TRiC) from the eukaryotic cytosol. A dendrogram of this family of chaperonins contains eight eukaryotic branches of TRiC subunits and one archaebacterial branch of thermosome subunits. Alignment of thermosome/TRiC sequences with eubacterial and eukaryotic Hsp60 sequences reveals a statistically significant similarity in two large N- and C-terminal blocks of sequence. Based on this alignment and on the recently published crystal structure of GroEL, we propose that subunits of the thermosome/TRiC family of chaperonins have a similar equatorial domain and overall domain topology as GroEL but differ in the structure of the apical domain.
嗜热栖热菌的伴侣蛋白热体由两个亚基（分子量分别为58,000和60,000）组成，它们组装成具有假八重旋转对称性的圆柱形复合物。这两个亚基的序列彼此之间以及与来自柴田硫化叶菌的TF55大约60%相同，与真核细胞质中含TCP1的环复合物（TRiC）的亚基有30 - 40%相同。这个伴侣蛋白家族的系统发育树包含TRiC亚基的八个真核分支和热体亚基的一个古细菌分支。热体/TRiC序列与真细菌和真核Hsp60序列的比对显示，在两个大的N端和C端序列块中存在统计学上显著的相似性。基于这种比对以及最近发表的GroEL晶体结构，我们提出热体/TRiC家族伴侣蛋白的亚基具有与GroEL相似的赤道结构域和整体结构域拓扑，但顶端结构域的结构不同。
