Cao Shiyun, Engilberge Sylvain, Girard Eric, Gabel Frank, Franzetti Bruno, Maupin-Furlow Julie A
Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA.
Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, 38044 Grenoble, France.
Structure. 2017 Jun 6;25(6):823-833.e6. doi: 10.1016/j.str.2017.04.002. Epub 2017 May 4.
JAMM/MPN metalloproteases cleave (iso)peptide bonds C-terminal to ubiquitin (Ub) and ubiquitin-like protein (Ubl) domains and typically require association with protein partners for activity, which has limited a molecular understanding of enzyme function. To provide an insight, we solved the X-ray crystal structures of a catalytically active Pyrococcus furiosus JAMM/MPN metalloprotease (PfJAMM1) alone and in complex with a Ubl (PfSAMP2) to 1.7- to 1.9-Å resolution. PfJAMM1 was found to have a redox sensitive dimer interface. In the PfJAMM1-bound state of the SAMP2, a Ubl-to-Ub conformational change was detected. Surprisingly, distant homologs of PfJAMM1 were found to be closely related in 3D structure, including the interface for Ubl/Ub binding. From this work, we infer the molecular basis of how JAMM/MPN proteases recognize and cleave Ubl/Ub tags from diverse proteins and highlight an α2-helix structural element that is conserved and crucial for binding and removing the Ubl SAMP2 tag.
JAMM/MPN金属蛋白酶切割泛素（Ub）和泛素样蛋白（Ubl）结构域C末端的（异）肽键，并且通常需要与蛋白质伴侣结合才能发挥活性，这限制了对酶功能的分子理解。为了深入了解，我们解析了嗜热栖热菌JAMM/MPN金属蛋白酶（PfJAMM1）单独以及与Ubl（PfSAMP2）形成复合物时的X射线晶体结构，分辨率达到1.7至1.9埃。发现PfJAMM1具有氧化还原敏感的二聚体界面。在SAMP2与PfJAMM1结合的状态下，检测到了从Ubl到Ub的构象变化。令人惊讶的是，发现PfJAMM1的远缘同源物在三维结构上密切相关，包括Ubl/Ub结合界面。通过这项工作，我们推断出JAMM/MPN蛋白酶如何从多种蛋白质中识别和切割Ubl/Ub标签的分子基础，并突出了一个保守的α2螺旋结构元件，该元件对于结合和去除Ubl SAMP2标签至关重要。
