A novel aminopeptidase associated with the 60 kDa chaperonin in the thermophilic archaeon Sulfolobus solfataricus
A novel aminopeptidase associated with the 60 kDa chaperonin in the thermophilic archaeon Sulfolobus solfataricus
复制标题
DOI：
10.1046/j.1365-2958.1998.00971.x
复制
发表时间：
1998-08-01
影响因子：
3.6
通讯作者：
Londei, P
中科院分区：
文献类型：
--
作者：
Condò, I;Ruggero, D;Londei, P
伴侣蛋白是具有特征性双环环形形状的高分子量蛋白质复合物;它们被认为有助于变性或新合成的多肽的折叠。这些蛋白质作为两个功能相似但亲缘关系较远的家族存在，一个包括细菌和细胞器伴侣蛋白，另一个（称为CCT-TRiC家族）包括细菌和真核生物的伴侣蛋白。CT-TRiC伴侣蛋白，特别是它们的原始成员，不如它们的细菌对应物那么为人所知，并且它们的主要细胞功能仍然是可疑的。在这项工作中，我们报告的伴侣蛋白的嗜热古菌硫磺硫化叶菌相互作用的几个多肽以外的两个亚基，构成的18-mer双环结构。我们已经克隆和测序的基因编码一个90 kDa的伴侣蛋白相关的蛋白，并已显示，使用生化分析，该产品是一种酶属于锌依赖性氨基肽酶家族，硫化叶菌蛋白显示最大的同源性真核生物（酵母和小鼠）氨基肽酶。它含有亮氨酸拉链基序，可以被细胞提取物中存在的未鉴定的激酶磷酸化。氨肽酶和伴侣蛋白之间的关联的可能意义进行了讨论。
The chaperonins are high-molecular-weight protein complexes having a characteristic double-ring toroidal shape; they are thought to aid the folding of denatured or newly synthesized polypeptides. These proteins exist as two functionally similar but distantly related families, one including the bacterial and organellar chaperonins and the other (termed the CCT-TRiC family) including the chaperonins of the Archaea and the eukaryotes. The CCT-TRiC chaperonins, particularly their archeal members, are less well known than their bacterial counterparts, and their main cellular function is still doubtful. In this work, we report that the chaperonin of the thermophilic archaeon Sulfolobus solfataricus interacts with several polypeptides other than the two subunits that constitute the 18-mer double-ring structure. We have cloned and sequenced the gene encoding one 90 kDa chaperonin-associated protein and have shown, using biochemical assays, that the product is an enzyme belonging to the family of zinc-dependent aminopeptidases, The Sulfolobus protein shows maximal homology to eukaryotic (yeast and mouse) aminopeptidases. It contains a leucine zipper motif and can be phosphorylated by an unidentified kinase present in the cell extracts. The possible significance of an association between an aminopeptidase and a chaperonin is discussed.