Institute of Technical Microbiology, Technical University Hamburg-Harburg, Kasernenstr. 12, 21073, Hamburg, Germany.
Appl Microbiol Biotechnol. 2010 Jun;87(2):479-89. doi: 10.1007/s00253-010-2628-x. Epub 2010 May 7.
Inteins are internal protein elements that self-excise from their host protein and catalyze ligation of the flanking sequences (exteins) with a peptide bond. They are found in organisms in all three domains of life, and in viral proteins. Intein excision is a posttranslational process that does not require auxiliary enzymes or cofactors. This self-excision process is called protein splicing, by analogy to the splicing of RNA introns from pre-mRNA. Protein splicing involves only four intramolecular reactions, and a small number of key catalytic residues in the intein and exteins. Protein-splicing can also occur in trans. In this case, the intein is separated into N- and C-terminal domains, which are synthesized as separate components, each joined to an extein. The intein domains reassemble and link the joined exteins into a single functional protein. Understanding the cis- and trans-protein splicing mechanisms led to the development of intein-mediated protein-engineering applications, such as protein purification, ligation, cyclization, and selenoprotein production. This review summarizes the catalytic activities and structures of inteins, and focuses on the advantages of some recent intein applications in molecular biology and biotechnology.
内肽是一种内在的蛋白质元件，它能够从宿主蛋白质中自我切除，并催化侧翼序列（外肽）之间形成肽键。它们存在于所有三个生命领域的生物中，以及病毒蛋白中。内肽切除是一种翻译后过程，不需要辅助酶或辅因子。这个自我切除过程被称为蛋白质剪接，类似于前体 mRNA 中的 RNA 内含子的剪接。蛋白质剪接只涉及四个分子内反应，以及内肽和外肽中的少数关键催化残基。蛋白质剪接也可以发生在转位。在这种情况下，内肽被分成 N-和 C-末端结构域，这些结构域被合成作为单独的成分，每个都与一个外肽相连。内肽结构域重新组装并将连接的外肽连接成单个功能性蛋白质。对内肽的顺式和反式蛋白质剪接机制的理解导致了内肽介导的蛋白质工程应用的发展，如蛋白质纯化、连接、环化和硒蛋白生产。这篇综述总结了内肽的催化活性和结构，并重点介绍了一些最近在内肽在分子生物学和生物技术中的应用的优势。
