| Institution: | 1. Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States;2. Molecular Oncology Department, Moffitt Cancer Center, Tampa, FL 33612, United States;1. Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA;2. University of Texas Southwestern Medical Center, Dallas, TX 75390, USA;3. Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA;1. Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, Kansas City, KS 66160, United States;2. Eye Research Institute, Oakland University, Rochester, MI 48309, United States;3. Department of Chemistry, Lehigh University, Bethlehem, PA 18015, United States;1. College of Chemical and Biological Engineering & ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310058, China;2. Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, United Kingdom;3. Research Centre of Biological Computation, Zhejiang Laboratory, Hangzhou 311100, China;1. State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China;2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China;3. School of Life Sciences, University of Science and Technology of China, Hefei 230026, China;4. Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China;1. Lab No. 606, Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India;2. Biophysical Chemistry & Structural Biology Laboratory, UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai, Vidyanagari Campus, Mumbai 400098, India |
| Abstract: | Eukaryotic post-translational arginylation, mediated by the family of enzymes known as the arginyltransferases (ATE1s), is an important post-translational modification that can alter protein function and even dictate cellular protein half-life. Multiple major biological pathways are linked to the fidelity of this process, including neural and cardiovascular developments, cell division, and even the stress response. Despite this significance, the structural, mechanistic, and regulatory mechanisms that govern ATE1 function remain enigmatic. To that end, we have used X-ray crystallography to solve the crystal structure of ATE1 from the model organism Saccharomyces cerevisiae ATE1 (ScATE1) in the apo form. The three-dimensional structure of ScATE1 reveals a bilobed protein containing a GCN5-related N-acetyltransferase (GNAT) fold, and this crystalline behavior is faithfully recapitulated in solution based on size-exclusion chromatography-coupled small angle X-ray scattering (SEC-SAXS) analyses and cryo-EM 2D class averaging. Structural superpositions and electrostatic analyses point to this domain and its domain-domain interface as the location of catalytic activity and tRNA binding, and these comparisons strongly suggest a mechanism for post-translational arginylation. Additionally, our structure reveals that the N-terminal domain, which we have previously shown to bind a regulatory Fe-S] cluster, is dynamic and disordered in the absence of metal bound in this location, hinting at the regulatory influence of this region. When taken together, these insights bring us closer to answering pressing questions regarding the molecular-level mechanism of eukaryotic post-translational arginylation. |
