title: Crystal structure of Escherichia coli methionyl-tRNA synthetase highlights species-specific features.
abstract: The 3D structure of monomeric C-truncated Escherichia coli methionyl-tRNA synthetase, a class 1 aminoacyl-tRNA synthetase, has been solved at 2.0 A resolution. Remarkably, the polypeptide connecting the two halves of the Rossmann fold exposes two identical knuckles related by a 2-fold axis but with zinc in the distal knuckle only. Examination of available MetRS orthologs reveals four classes according to the number and zinc content of the putative knuckles. Extreme cases are exemplified by the MetRS of eucaryotic or archaeal origin, where two knuckles and two metal ions are expected, and by the mitochondrial enzymes, which are predicted to have one knuckle without metal ion.
authors.affiliation: Laboratoire de Biochimie, Ecole Polytechnique, CNRS UMR 7654, Palaiseau Cedex, F-91128, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Mechulam
authors.forename: E
authors.initials: E
authors.lastname: Schmitt
authors.forename: L
authors.initials: L
authors.lastname: Maveyraud
authors.forename: C
authors.initials: C
authors.lastname: Zelwer
authors.forename: O
authors.initials: O
authors.lastname: Nureki
authors.forename: S
authors.initials: S
authors.lastname: Yokoyama
authors.forename: M
authors.initials: M
authors.lastname: Konno
authors.forename: S
authors.initials: S
authors.lastname: Blanquet
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000926:Anticodon / Q000378:metabolism; D001665:Binding Sites; D020134:Catalytic Domain; D003460:Crystallization; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D006801:Humans; D008718:Methionine-tRNA Ligase / Q000737:chemistry* / Q000145:classification*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D012343:RNA, Transfer / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D055672:Static Electricity; D015032:Zinc / Q000378:metabolism
chemical_list: D000926:Anticodon; D012343:RNA, Transfer; D008718:Methionine-tRNA Ligase; D015032:Zinc