The Chaperonins of Synechocystis PCC 6803 differ in heat inducibility and chaperone activity
The Chaperonins of Synechocystis PCC 6803 differ in heat inducibility and chaperone activity
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DOI：
10.1006/bbrc.2001.6083
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发表时间：
2001-12-14
影响因子：
3.1
通讯作者：
Vígh, L
中科院分区：
文献类型：
--
作者：
Kovács, E;van der Vies, SM;Vígh, L
伴侣蛋白 GroEL 和 Cpn60 从蓝藻集胞藻 PCC 6803 中分离出来并进行表征。在最佳条件下生长的细胞中，它们的比例约为一比一。然而，响应热应激，GroEL 的量比 Cpn60 的量增加得多。不稳定的伴侣蛋白低聚物在分离过程中需要通过 MgATP 或甘油进行稳定。使用大肠杆菌突变株 groEL44 揭示了两种蓝藻伴侣蛋白的功能特性显着不同。蓝藻 GroEL 在大肠杆菌突变株中的过度表达使其能够在高温下生长、形成成熟噬菌体 T4 以及活性 Rubisco 酶组装。相比之下，Cpn60部分补充了温度敏感表型、Rubisco组装缺陷，并且不促进噬菌体T4的生长。两种蓝藻伴侣蛋白的伴侣活性差异很可能反映了集胞藻 PCC 6803 生命期间所需的独特伴侣蛋白特性。(C) 2001 Elsevier Science。
The chaperonins GroEL and Cpn60 were isolated from the cyanobacterium Synechocystis PCC 6803 and characterized. In cells grown under optimal conditions their ratio was about one to one. However, the amount of GroEL increased considerably more than that of Cpn60 in response to heat stress. The labile chaperonin oligomer required stabilization by MgATP or glycerol during isolation. Use of the E. coli mutant strain, groEL44 revealed that the functional properties of the two cyanobacterial chaperonins are strikingly different. Overexpression of cyanobacterial GroEL in the E. coli mutant strain allowed growth at elevated temperature, the formation of mature bacteriophage T4, and active Rubisco enzyme assembly. In contrast, Cpn60 partially complemented the temperature-sensitive phenotype, the Rubisco assembly defect and did not promote the growth of the bacteriophage T4. The difference in chaperone activity of the two cyanobacterial chaperonins very probably reflects the unique chaperonin properties required during the life of Synechocystis PCC 6803. (C) 2001 Elsevier Science.