title: Dissection of the structural organization of the aminoacyl-tRNA synthetase complex.
abstract: The spatio-temporal organization of proteins within the cytoplasm of eukaryotic cells rests in part on the assembly of stable and transient multiprotein complexes. Here we examined the assembly of the multiaminoacyl-tRNA synthetase complex (MARS) in human cells. This complex contains nine aminoacyl-tRNA synthetases and three auxiliary proteins and is a hallmark of metazoan species. Isolation of the complexes has been performed by tandem affinity purification from human cells in culture. To understand the rules of assembly of this particle, expression of the three nonsynthetase components of MARS, p18, p38, and p43, was blocked by stable small interfering RNA silencing. The lack of these components was not lethal for the cells, but cell growth was slightly reduced. The residual complexes that could form in vivo in the absence of the auxiliary proteins were isolated by tandem affinity purification. From the repertoire of the subcomplexes that could be isolated, a comprehensive map of protein-protein interactions mediating complex assembly is deduced. The data are consistent with a structural role of the three nonsynthetase components of MARS, with p38 connecting two subcomplexes that may form in the absence of p38.
authors.affiliation: Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, 1 Ave. de la Terrasse, 91190 Gif-sur-Yvette, France.
authors.forename: Monika
authors.initials: M
authors.lastname: Kaminska
authors.forename: Svitlana
authors.initials: S
authors.lastname: Havrylenko
authors.forename: Paulette
authors.initials: P
authors.lastname: Decottignies
authors.forename: Sylvie
authors.initials: S
authors.lastname: Gillet
authors.forename: Pierre
authors.initials: P
authors.lastname: Le Maréchal
authors.forename: Boris
authors.initials: B
authors.lastname: Negrutskii
authors.forename: Marc
authors.initials: M
authors.lastname: Mirande
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D046912:Multiprotein Complexes / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D020836:Protein Structure, Quaternary / Q000502:physiology; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: D046912:Multiprotein Complexes; D034741:RNA, Small Interfering; D000604:Amino Acyl-tRNA Synthetases; C101946:p18 component, aminoacyl tRNA synthetase