A systematic survey of in vivo obligate chaperonin-dependent substrates
A systematic survey of in vivo obligate chaperonin-dependent substrates
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DOI：
10.1038/emboj.2010.52
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发表时间：
2010-05-05
期刊：
影响因子：
11.4
通讯作者：
Taguchi, Hideki
中科院分区：
文献类型：
--
作者：
Fujiwara, Kei;Ishihama, Yasushi;Taguchi, Hideki
伴侣蛋白是细胞中蛋白质子集折叠所必需的。大肠杆菌伴侣蛋白GroEL/GroES（GroE）相互作用的早期蛋白质组分析预测专性伴侣蛋白底物，这被称为III类底物。然而，在体内折叠的伴侣蛋白的要求还没有得到充分的研究。在这里，我们使用条件GroE表达菌株全面评估了伴侣蛋白的需求，并得出结论，只有60%的III类底物是体内真正的专性GroE底物。体内专性底物与新鉴定的专性底物结合，称为IV类底物。IV类底物仅限于分子量可包封在伴侣蛋白空腔中的蛋白质，富含丙氨酸/甘氨酸残基，并且对易于聚集的折叠具有强烈的结构偏好。值得注意的是，类似于70%的IV类底物似乎是代谢酶，支持GroE在酶进化中的假设作用。The EMBO Journal（2010）29，1552-1564. doi：10.1038/doj.2010.52; 2010年4月1日在线发布
Chaperonins are absolutely required for the folding of a subset of proteins in the cell. An earlier proteome-wide analysis of Escherichia coli chaperonin GroEL/GroES (GroE) interactors predicted obligate chaperonin substrates, which were termed Class III substrates. However, the requirement of chaperonins for in vivo folding has not been fully examined. Here, we comprehensively assessed the chaperonin requirement using a conditional GroE expression strain, and concluded that only similar to 60% of Class III substrates are bona fide obligate GroE substrates in vivo. The in vivo obligate substrates, combined with the newly identified obligate substrates, were termed Class IV substrates. Class IV substrates are restricted to proteins with molecular weights that could be encapsulated in the chaperonin cavity, are enriched in alanine/glycine residues, and have a strong structural preference for aggregation-prone folds. Notably, similar to 70% of the Class IV substrates appear to be metabolic enzymes, supporting a hypothetical role of GroE in enzyme evolution. The EMBO Journal (2010) 29, 1552-1564. doi:10.1038/emboj.2010.52; Published online 1 April 2010