title: Structural basis of RNA-dependent recruitment of glutamine to the genetic code.
abstract: Glutaminyl-transfer RNA (Gln-tRNA(Gln)) in archaea is synthesized in a pretranslational amidation of misacylated Glu-tRNA(Gln) by the heterodimeric Glu-tRNA(Gln) amidotransferase GatDE. Here we report the crystal structure of the Methanothermobacter thermautotrophicus GatDE complexed to tRNA(Gln) at 3.15 angstroms resolution. Biochemical analysis of GatDE and of tRNA(Gln) mutants characterized the catalytic centers for the enzyme's three reactions (glutaminase, kinase, and amidotransferase activity). A 40 angstrom-long channel for ammonia transport connects the active sites in GatD and GatE. tRNA(Gln) recognition by indirect readout based on shape complementarity of the D loop suggests an early anticodon-independent RNA-based mechanism for adding glutamine to the genetic code.
authors.affiliation: Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Oshikane
authors.forename: Kelly
authors.initials: K
authors.lastname: Sheppard
authors.forename: Shuya
authors.initials: S
authors.lastname: Fukai
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Ishitani
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Numata
authors.forename: R Lynn
authors.initials: RL
authors.lastname: Sherrer
authors.forename: Liang
authors.initials: L
authors.lastname: Feng
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Schmitt
authors.forename: Michel
authors.initials: M
authors.lastname: Panvert
authors.forename: Sylvain
authors.initials: S
authors.lastname: Blanquet
authors.forename: Yves
authors.initials: Y
authors.lastname: Mechulam
authors.forename: Dieter
authors.initials: D
authors.lastname: Söll
authors.forename: Osamu
authors.initials: O
authors.lastname: Nureki
mesh_terms: D000215:Acylation; D000255:Adenosine Triphosphate / Q000378:metabolism; D000641:Ammonia / Q000378:metabolism; D000926:Anticodon; D001665:Binding Sites; D020134:Catalytic Domain; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D019281:Dimerization; D005815:Genetic Code; D005973:Glutamine / Q000378:metabolism*; D006860:Hydrogen Bonding; D008274:Magnesium / Q000378:metabolism; D017013:Methanobacteriaceae / Q000201:enzymology* / Q000235:genetics; D008958:Models, Molecular; D009154:Mutation; D019884:Nitrogenous Group Transferases / Q000737:chemistry* / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D019642:RNA, Archaeal / Q000737:chemistry* / Q000378:metabolism; D012351:RNA, Transfer, Gln / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000926:Anticodon; D019642:RNA, Archaeal; D012351:RNA, Transfer, Gln; D005973:Glutamine; D000641:Ammonia; D000255:Adenosine Triphosphate; D019884:Nitrogenous Group Transferases; C047694:glutamyl-tRNA(Gln) amidotransferase; D008274:Magnesium