title: Structure of eEF3 and the mechanism of transfer RNA release from the E-site.
abstract: Elongation factor eEF3 is an ATPase that, in addition to the two canonical factors eEF1A and eEF2, serves an essential function in the translation cycle of fungi. eEF3 is required for the binding of the aminoacyl-tRNA-eEF1A-GTP ternary complex to the ribosomal A-site and has been suggested to facilitate the clearance of deacyl-tRNA from the E-site. Here we present the crystal structure of Saccharomyces cerevisiae eEF3, showing that it consists of an amino-terminal HEAT repeat domain, followed by a four-helix bundle and two ABC-type ATPase domains, with a chromodomain inserted in ABC2. Moreover, we present the cryo-electron microscopy structure of the ATP-bound form of eEF3 in complex with the post-translocational-state 80S ribosome from yeast. eEF3 uses an entirely new factor binding site near the ribosomal E-site, with the chromodomain likely to stabilize the ribosomal L1 stalk in an open conformation, thus allowing tRNA release.
authors.affiliation: Centre for Structural Biology, Department of Molecular Biology, University of Aarhus, Gustav Wieds Vej 10C, DK-8000 Aarhus, Denmark.
authors.forename: Christian B F
authors.initials: CB
authors.lastname: Andersen
authors.forename: Thomas
authors.initials: T
authors.lastname: Becker
authors.forename: Michael
authors.initials: M
authors.lastname: Blau
authors.forename: Monika
authors.initials: M
authors.lastname: Anand
authors.forename: Mario
authors.initials: M
authors.lastname: Halic
authors.forename: Bharvi
authors.initials: B
authors.lastname: Balar
authors.forename: Thorsten
authors.initials: T
authors.lastname: Mielke
authors.forename: Thomas
authors.initials: T
authors.lastname: Boesen
authors.forename: Jan Skov
authors.initials: JS
authors.lastname: Pedersen
authors.forename: Christian M T
authors.initials: CM
authors.lastname: Spahn
authors.forename: Terri Goss
authors.initials: TG
authors.lastname: Kinzy
authors.forename: Gregers R
authors.initials: GR
authors.lastname: Andersen
authors.forename: Roland
authors.initials: R
authors.lastname: Beckmann
mesh_terms: D000244:Adenosine Diphosphate / Q000737:chemistry / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D001665:Binding Sites; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D015966:Gene Expression Regulation, Fungal; D008954:Models, Biological; D008958:Models, Molecular; D010445:Peptide Elongation Factors / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D011487:Protein Conformation; D012343:RNA, Transfer / Q000378:metabolism*; D012270:Ribosomes / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D029701:Saccharomyces cerevisiae Proteins; D013329:Structure-Activity Relationship
chemical_list: D005656:Fungal Proteins; D010445:Peptide Elongation Factors; D029701:Saccharomyces cerevisiae Proteins; C111584:YEF3 protein, S cerevisiae; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D012343:RNA, Transfer