The protein universe as we know is composed of folded structures and intrinsic disordered regions. The latter may adopt structures upon interaction with binding partners. In addition, some proteins contain C‐terminal extensions which act as independent functional units in the context of the protein. Since their activity does not depend on the protein context they can be considered as peptides in proteins. To illustrate this principle, we here discuss the C‐terminal extensions of IgM antibodies which dictate their assembly and the molecular chaperones Hsp90, Hsp70, and Hsp104 which use C‐terminal peptide extensions as a docking site for interaction with different co‐chaperones.

中文翻译：

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蛋白质中的肽。

我们所知的蛋白质宇宙由折叠结构和固有的无序区域组成。后者可以在与有约束力的伙伴相互作用时采用结构。此外，某些蛋白质包含C末端延伸，在蛋白质的上下文中充当独立的功能单元。由于它们的活性不依赖于蛋白质，因此可以将它们视为蛋白质中的肽。为了说明这一原理，我们在这里讨论决定其装配的IgM抗体的C末端延伸以及分子伴侣Hsp90，Hsp70和Hsp104，它们使用C末端肽延伸作为与不同伴侣分子相互作用的对接位点。