@article{c000502da6284a288aa3095c3610f8d0,
title = "Ribosomal Protein L11 Selectively Stabilizes a Tertiary Structure of the GTPase Center rRNA Domain",
abstract = "The GTPase Center (GAC) RNA domain in bacterial 23S rRNA is directly bound by ribosomal protein L11, and this complex is essential to ribosome function. Previous cocrystal structures of the 58-nucleotide GAC RNA bound to L11 revealed the intricate tertiary fold of the RNA domain, with one monovalent and several divalent ions located in specific sites within the structure. Here, we report a new crystal structure of the free GAC that is essentially identical to the L11-bound structure, which retains many common sites of divalent ion occupation. This new structure demonstrates that RNA alone folds into its tertiary structure with bound divalent ions. In solution, we find that this tertiary structure is not static, but rather is best described as an ensemble of states. While L11 protein cannot bind to the GAC until the RNA has adopted its tertiary structure, new experimental data show that L11 binds to Mg2+-dependent folded states, which we suggest lie along the folding pathway of the RNA. We propose that L11 stabilizes a specific GAC RNA tertiary state, corresponding to the crystal structure, and that this structure reflects the functionally critical conformation of the rRNA domain in the fully assembled ribosome.",
keywords = "GTPase center, L11 stalk, protein:RNA complex, RNA crystal structure, RNA folding",
author = "Robb Welty and Michael Rau and Suzette Pabit and Dunstan, {Mark S.} and Conn, {Graeme L.} and Lois Pollack and Hall, {Kathleen B.}",
note = "Funding Information: We thank Professor Roberto Galletto (WUSM) for the use of his stopped-flow spectrometer. 2AP-GAC RNAs were received from Agilent labs, and we thank Dr. Laura-Kay Bruhn and especially Dr. Doug Dellinger for 15N GAC RNAs. KBH and RW thank Professor David Draper for his gift of L11 CTD proteins. We thank members of the Pollack Lab of Cornell University and Richard Gillilan of Cornell High Energy Synchrotron Source (CHESS) for experimental assistance during SAXS measurements. Funding to LP is from the National Institutes of Health (R35-GM122514) and the National Science Foundation through a Science and Technology Center grant 1231306. CHESS is supported by the National Science Foundation award DMR-1332208, and the Macromolecular Diffraction at CHESS (MacCHESS) resource is supported by award GM-103485 from the National Institutes of Health. X-ray diffraction data collection was performed on beamline ID23-1 at the European Synchrotron Radiation Facility (ESRF), Grenoble, France, and we gratefully acknowledge the beamline staff for their assistance. This work was supported by the Wellcome Trust Grant 79242 to GLC. Funding Information: We thank Professor Roberto Galletto (WUSM) for the use of his stopped-flow spectrometer. 2AP-GAC RNAs were received from Agilent labs, and we thank Dr. Laura-Kay Bruhn and especially Dr. Doug Dellinger for 15 N GAC RNAs. KBH and RW thank Professor David Draper for his gift of L11 CTD proteins. We thank members of the Pollack Lab of Cornell University and Richard Gillilan of Cornell High Energy Synchrotron Source (CHESS) for experimental assistance during SAXS measurements. Funding to LP is from the National Institutes of Health ( R35-GM122514 ) and the National Science Foundation through a Science and Technology Center grant 1231306 . CHESS is supported by the National Science Foundation award DMR-1332208 , and the Macromolecular Diffraction at CHESS (MacCHESS) resource is supported by award GM-103485 from the National Institutes of Health . X-ray diffraction data collection was performed on beamline ID23-1 at the European Synchrotron Radiation Facility (ESRF), Grenoble, France, and we gratefully acknowledge the beamline staff for their assistance. This work was supported by the Wellcome Trust Grant 79242 to GLC. Publisher Copyright: {\textcopyright} 2019 Elsevier Ltd",
year = "2020",
month = feb,
day = "14",
doi = "10.1016/j.jmb.2019.12.010",
language = "English",
volume = "432",
pages = "991--1007",
journal = "Journal of molecular biology",
issn = "0022-2836",
publisher = "Academic Press, Ltd",
number = "4",
}