Elleuche Skander, Nolting Nicole, Pöggeler Stefanie
Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, 44780, Bochum, Germany.
Appl Microbiol Biotechnol. 2006 Oct;72(5):959-67. doi: 10.1007/s00253-006-0350-5. Epub 2006 Mar 17.
Inteins are protein-intervening sequences found inside the coding region of different host proteins and are translated in-frame with them. They can self-excise through protein splicing, which ligates the host protein flanks with a peptide bond. In this study, four different species of the genus Penicillium were investigated for the presence of inteins inside the conserved splicing-factor protein PRP8. We identified 157 to 162 amino acid in-frame insertions in the PRP8 protein of Penicillium chrysogenum, Penicillium expansum, and Penicillium vulpinum (formerly Penicillium claviforme). The Penicillium PRP8 inteins are mini-inteins without a conserved endonuclease domain. We demonstrated that the PRP8 mini-inteins of P. chrysogenum, P. expansum, and P. vulpinum undergo autocatalytic protein splicing when heterologously expressed in E. coli, in a model host protein, and in a divided GFP model system. They are, thus, among the smallest known nuclear-encoded, active splicing protein elements. The GFP assay should be valuable as a screening system for protein splicing inhibitors as potential antimycotic agents and as tools for studying the mechanism of protein splicing of fungal mini-inteins.
内含肽是在不同宿主蛋白编码区域内发现的蛋白质插入序列，并与它们一起进行框内翻译。它们可以通过蛋白质剪接进行自我切除，蛋白质剪接通过肽键连接宿主蛋白侧翼。在本研究中，对青霉属的四种不同物种进行了研究，以确定保守剪接因子蛋白PRP8内是否存在内含肽。我们在产黄青霉、扩展青霉和狐青霉（以前称为棒形青霉）的PRP8蛋白中鉴定出157至162个氨基酸的框内插入。青霉PRP8内含肽是没有保守核酸内切酶结构域的微型内含肽。我们证明，产黄青霉、扩展青霉和狐青霉的PRP8微型内含肽在大肠杆菌、模型宿主蛋白和分裂GFP模型系统中异源表达时会进行自催化蛋白质剪接。因此，它们是已知最小的核编码活性剪接蛋白元件之一。GFP检测作为蛋白质剪接抑制剂的筛选系统，作为潜在的抗真菌剂以及研究真菌微型内含肽蛋白质剪接机制的工具应该是有价值的。
