All dose-fractioned images were motion-corrected and dose-weighted by MotionCorr2(Zheng et al., 2017) software and their contrast transfer functions were estimated by ctffind4(Rohou and Grigorieff, 2015). A total of 2,039,214 particles were auto-picked using the model from SARS-CoV-2 Cap(−1)’-RTC (PDB: 7CYQ)(Yan et al., 2021) and extracted with a box size of 448 pixels in cryoSPARC(Punjani et al., 2017). The following 2D, 3D classifications and refinements were all performed in cryoSPARC. 887,588 particles were selected after two rounds of 2D classification based on complex integrity. This particle set was used to do Ab-Initio reconstruction in five classes, which were then used as 3D volume templates for heterogeneous refinement, with 135,801 particles converged into dCap(0)-RTC complex class and 80,256 particles converged into mCap(0)-RTC complex class. Next, these particles were imported into RELION 3.03(Scheres, 2012) to perform local classification to obtain one class particle with final resolution 3.35 Å and 3.78 Å, respectively. The methods are described in Figures S2 and andS4S4.

Note: The content above has been extracted from a research article, so it may not display correctly.

Please log in to submit your questions online.
Your question will be posted on the Bio-101 website. We will send your questions to the authors of this protocol and Bio-protocol community members who are experienced with this method. you will be informed using the email address associated with your Bio-protocol account.

We use cookies on this site to enhance your user experience. By using our website, you are agreeing to allow the storage of cookies on your computer.