| Autor: |
Maio N; Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892., Raza MK; Department of Chemistry, The Pennsylvania State University, University Park, PA 16802., Li Y; National Institute of Neurological Disorders and Stroke, NIH, Proteomics Core Facility, Bethesda, MD 20892., Zhang DL; Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892., Bollinger JM Jr; Department of Chemistry, The Pennsylvania State University, University Park, PA 16802.; Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802., Krebs C; Department of Chemistry, The Pennsylvania State University, University Park, PA 16802.; Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802., Rouault TA; Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892. |
| Abstrakt: |
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, uses an RNA-dependent RNA polymerase along with several accessory factors to replicate its genome and transcribe its genes. Nonstructural protein (nsp) 13 is a helicase required for viral replication. Here, we found that nsp13 ligates iron, in addition to zinc, when purified anoxically. Using inductively coupled plasma mass spectrometry, UV-visible absorption, EPR, and Mössbauer spectroscopies, we characterized nsp13 as an iron-sulfur (Fe-S) protein that ligates an Fe 4 S 4 cluster in the treble-clef metal-binding site of its zinc-binding domain. The Fe-S cluster in nsp13 modulates both its binding to the template RNA and its unwinding activity. Exposure of the protein to the stable nitroxide TEMPOL oxidizes and degrades the cluster and drastically diminishes unwinding activity. Thus, optimal function of nsp13 depends on a labile Fe-S cluster that is potentially targetable for COVID-19 treatment. |
