title: Structure of the Kti11/Kti13 heterodimer and its double role in modifications of tRNA and eukaryotic elongation factor 2.
abstract: The small, highly conserved Kti11 alias Dph3 protein encoded by the Kluyveromyces lactis killer toxin insensitive gene KTI11/DPH3 is involved in the diphthamide modification of eukaryotic elongation factor 2 and, together with Kti13, in Elongator-dependent tRNA wobble base modifications, thereby affecting the speed and accuracy of protein biosynthesis through two distinct mechanisms. We have solved the crystal structures of Saccharomyces cerevisiae Kti13 and the Kti11/Kti13 heterodimer at 2.4 and 2.9 Å resolution, respectively, and validated interacting residues through mutational analysis in vitro and in vivo. We show that metal coordination by Kti11 and its heterodimerization with Kti13 are essential for both translational control mechanisms. Our structural and functional analyses identify Kti13 as an additional component of the diphthamide modification pathway and provide insight into the molecular mechanisms that allow the Kti11/Kti13 heterodimer to coregulate two consecutive steps in ribosomal protein synthesis.
authors.affiliation: Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Glatt
authors.affiliation: Martin-Luther-Universität Halle-Wittenberg, Institut für Biologie, Weinbergweg 10, 06120 Halle (Saale), Germany.
authors.forename: Rene
authors.initials: R
authors.lastname: Zabel
authors.affiliation: Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany.
authors.forename: Ivana
authors.initials: I
authors.lastname: Vonkova
authors.affiliation: Martin-Luther-Universität Halle-Wittenberg, Institut für Physik, Betty-Heimann-Straße 7, 06120 Halle (Saale), Germany.
authors.forename: Amit
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Institut für Zytobiologie, Philipps-Universität Marburg, Robert-Koch-Straße 6, 35037 Marburg, Germany.
authors.forename: Daili J
authors.initials: DJ
authors.lastname: Netz
authors.affiliation: Institut für Zytobiologie, Philipps-Universität Marburg, Robert-Koch-Straße 6, 35037 Marburg, Germany.
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Pierik
authors.affiliation: Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Rybin
authors.affiliation: Institut für Zytobiologie, Philipps-Universität Marburg, Robert-Koch-Straße 6, 35037 Marburg, Germany; LOEWE Zentrum für Synthetische Mikrobiologie SynMikro, Hans-Meerwein-Straße, 35043 Marburg, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Lill
authors.affiliation: Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany.
authors.forename: Anne-Claude
authors.initials: AC
authors.lastname: Gavin
authors.affiliation: Martin-Luther-Universität Halle-Wittenberg, Institut für Physik, Betty-Heimann-Straße 7, 06120 Halle (Saale), Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Balbach
authors.affiliation: Martin-Luther-Universität Halle-Wittenberg, Institut für Biologie, Weinbergweg 10, 06120 Halle (Saale), Germany. Electronic address: karin.breunig@genetik.uni-halle.de.
authors.forename: Karin D
authors.initials: KD
authors.lastname: Breunig
authors.affiliation: Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany. Electronic address: cmueller@embl.de.
authors.forename: Christoph W
authors.initials: CW
authors.lastname: Müller
mesh_terms: D008958:Models, Molecular; D030781:Organisms, Genetically Modified; D020652:Peptide Elongation Factor 2 / Q000737:chemistry / Q000378:metabolism*; D014176:Protein Biosynthesis / Q000235:genetics; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics; D012343:RNA, Transfer / Q000737:chemistry / Q000378:metabolism*; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*
chemical_list: C089099:ATS1 protein, S cerevisiae; C459979:KTI11 protein, S cerevisiae; D020652:Peptide Elongation Factor 2; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D012343:RNA, Transfer