title: Ribosomal protein uS19 mutants reveal its role in coordinating ribosome structure and function.
abstract: Prior studies identified allosteric information pathways connecting functional centers in the large ribosomal subunit to the decoding center in the small subunit through the B1a and B1b/c intersubunit bridges in yeast. In prokaryotes a single SSU protein, uS13, partners with H38 (the A-site finger) and uL5 to form the B1a and B1b/c bridges respectively. In eukaryotes, the SSU component was split into 2 separate proteins during the course of evolution. One, also known as uS13, participates in B1b/c bridge with uL5 in eukaryotes. The other, called uS19 is the SSU partner in the B1a bridge with H38. Here, polyalanine mutants of uS19 involved in the uS19/uS13 and the uS19/H38 interfaces were used to elucidate the important amino acid residues involved in these intersubunit communication pathways. Two key clusters of amino acids were identified: one located at the junction between uS19 and uS13, and a second that appears to interact with the distal tip of H38. Biochemical analyses reveal that these mutations shift the ribosomal rotational equilibrium toward the unrotated state, increasing ribosomal affinity for tRNAs in the P-site and for ternary complex in the A-site, and inhibit binding of the translocase, eEF2. These defects in turn affect specific aspects of translational fidelity. These findings suggest that uS19 plays a critical role as a conduit of information exchange between the large and small ribosomal subunits directly through the B1a, and indirectly through the B1b/c bridges.
authors.affiliation: Department of Chemistry and Biochemistry; University of Maryland ; College Park, MD USA.
authors.forename: Alicia M
authors.initials: AM
authors.lastname: Bowen
authors.affiliation: Department of Cell Biology and Molecular Genetics; University of Maryland ; College Park, MD USA.
authors.forename: Sharmishtha
authors.initials: S
authors.lastname: Musalgaonkar
authors.affiliation: Department of Cell Biology and Molecular Genetics; University of Maryland ; College Park, MD USA.
authors.forename: Christine A
authors.initials: CA
authors.lastname: Moomau
authors.affiliation: Department of Cell Biology and Molecular Genetics; University of Maryland ; College Park, MD USA.
authors.forename: Suna P
authors.initials: SP
authors.lastname: Gulay
authors.affiliation: Department of Cell Biology and Molecular Genetics; University of Maryland ; College Park, MD USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Mirvis
authors.affiliation: Department of Cell Biology and Molecular Genetics; University of Maryland ; College Park, MD USA.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Dinman
keywords: intersubunit bridges; ribosome; translational fidelity; uS19; yeast
references.citation: Structure. 2009 Dec 9;17(12):1591-604
references.pmid: 20004163
references.citation: Gene. 1999 Jul 8;234(2):187-208
references.pmid: 10395892
references.citation: Nucleic Acids Res. 2004 Nov 23;32(20):e160
references.pmid: 15561995
references.citation: Nucleic Acids Res. 2014 Feb;42(3):2049-63
references.pmid: 24214990
references.citation: Microbiol Mol Biol Rev. 2007 Sep;71(3):477-94
references.pmid: 17804668
references.citation: Biochimie. 2010 Jul;92(7):820-5
references.pmid: 20206660
references.citation: Nucleic Acids Res. 2010 Dec;38(22):8377-89
references.pmid: 20705654
references.citation: Cell. 2014 Jul 3;158(1):121-31
references.pmid: 24995983
references.citation: J Biol Chem. 2006 Oct 27;281(43):32639-48
references.pmid: 16950777
references.citation: Annu Rev Biophys Biomol Struct. 2006;35:299-317
references.pmid: 16689638
references.citation: Mol Biol (Mosk). 2006 Jul-Aug;40(4):658-68
references.pmid: 16913225
references.citation: PLoS One. 2011;6(5):e20048
references.pmid: 21625514
references.citation: Mol Cell Biol. 2006 Dec;26(23):8992-9002
references.pmid: 17000775
references.citation: J Biol Chem. 2009 May 1;284(18):11761-5
references.pmid: 19117941
references.citation: Cell. 1989 Sep 8;58(5):857-67
references.pmid: 2673535
references.citation: Science. 2009 Aug 21;325(5943):1014-7
references.pmid: 19696352
references.citation: Mol Cell. 2007 Apr 13;26(1):41-50
references.pmid: 17434125
references.citation: Nucleic Acids Res. 2014 Dec 1;42(21):13384-92
references.pmid: 25389262
references.citation: RNA. 2008 Oct;14(10):1979-90
references.pmid: 18772246
references.citation: Nature. 2000 Jul 20;406(6793):318-22
references.pmid: 10917535
references.citation: Science. 2011 Dec 16;334(6062):1524-9
references.pmid: 22096102
references.citation: Proc Natl Acad Sci U S A. 2008 Nov 4;105(44):16924-7
references.pmid: 18971332
references.citation: Nature. 2010 Dec 2;468(7324):713-6
references.pmid: 21124459
references.citation: Curr Opin Struct Biol. 2012 Dec;22(6):759-67
references.pmid: 22884264
references.citation: Gene. 2007 Nov 15;403(1-2):1-5
references.pmid: 17869453
references.citation: Annu Rev Biophys. 2010;39:227-44
references.pmid: 20192776
references.citation: Science. 2010 Oct 15;330(6002):369-72
references.pmid: 20947765
references.citation: Curr Opin Struct Biol. 2012 Dec;22(6):778-85
references.pmid: 22906732
references.citation: Curr Opin Struct Biol. 2014 Feb;24:165-9
references.pmid: 24524803
references.citation: Nat Protoc. 2006;1(3):1610-6
references.pmid: 17406453
references.citation: J Virol. 1992 Jun;66(6):3669-76
references.pmid: 1583726
references.citation: RNA. 2003 Aug;9(8):1019-24
references.pmid: 12869712
references.citation: Nucleic Acids Res. 1997 Dec 15;25(24):4872-5
references.pmid: 9396790
references.citation: PLoS One. 2007 Jun 13;2(6):e517
references.pmid: 17565370
references.citation: EMBO J. 2004 Jun 16;23(12):2336-47
references.pmid: 15167894
references.citation: Nucleic Acids Res. 2010 Nov;38(21):7800-13
references.pmid: 20660012
references.citation: Mol Cell Biol. 1991 May;11(5):2723-35
references.pmid: 2017175
references.citation: Proc Natl Acad Sci U S A. 2007 Mar 20;104(12):4881-5
references.pmid: 17360328
references.citation: Nucleic Acids Res. 2008 Nov;36(19):6175-86
references.pmid: 18832371
references.citation: J Bacteriol. 1983 Jan;153(1):163-8
references.pmid: 6336730