bioRxiv preprint doi: https://doi.org/10.1101/2020.01.07.897827; this version posted January 8, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Receptor compaction and GTPase movements drive cotranslational protein translocation Jae Ho Lee1, SangYoon Chung2, Yu-Hsien Hwang Fu1,a, Ruilin Qian1,b, Xuemeng Sun1,c, Shimon Weiss2,3, Shu-ou Shan1* 1Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125 2Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA 90095 3Department of Physics, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, 52900, Israel aCurrent address: Department of Biochemistry, Stanford University, Stanford, CA, 94305 bCurrent address: Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China cCurrent address: Department of Chemistry, Princeton University, Princeton, NJ, 08544 *corresponding author. Email:
[email protected] Keywords: Protein Targeting, Signal Recognition Particle, Single Molecule Spectroscopy, GTPase, Ribosome, Protein Dynamics Short Title: SRP receptor compaction drives protein targeting bioRxiv preprint doi: https://doi.org/10.1101/2020.01.07.897827; this version posted January 8, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Abstract Signal recognition particle (SRP) is a universally conserved targeting machine that couples the synthesis of ~30% of the proteome to their proper membrane localization1,2.