Evidence for similar structural organization of the multienzyme aminoacyl-tRNA synthetase complex in vivo and in vitro

• Published in: The Journal of biological chemistry Vol. 269; no. 26; pp. 17375 - 17378
• Main Authors: FILONENKO, V. V, DEUTSCHER, M. P
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Biochemistry and Molecular Biology 01-07-1994
• Subjects: Amino Acyl-tRNA Synthetases - chemistry; Amino Acyl-tRNA Synthetases - immunology; Amino Acyl-tRNA Synthetases - isolation & purification; Analytical, structural and metabolic biochemistry; Animals; Antibodies, Monoclonal; Antibody Specificity; Biological and medical sciences; Cells, Cultured; Cross-Linking Reagents; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Kidney - enzymology; Ligases; Precipitin Tests; Protein Conformation; Rabbits; Arginine-tRNA ligase; In vivo; Immunoprecipitation reaction; Chemical modification; Multienzyme complex; Molecular structure; Enzyme; Ligases; Immunoblotting assay; Crosslinking; Carbon-oxygen ligases; In vitro
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(17)32446-8

Although aminoacyl-tRNA synthetases from higher eukaryotic cells are routinely isolated as components of a multienzyme complex,
it has remained unclear how closely the isolated complex reflects a structure that exists within the cell. To answer this
question, we have used chemical cross-linking and immunological detection to identify the nearest neighbor(s) of arginyl-tRNA
synthetase both in the isolated, purified complex and in saponin-permeabilized cells, which retain much of the structural
organization of intact cells. Our results show that arginyl-tRNA synthetase is cross-linked primarily both in vitro and in
vivo to a single protein, an as yet uncharacterized 38-kDa polypeptide known to be present in synthetase complexes from many
sources. These data demonstrate that the isolated, multienzyme amino-acyl-tRNA synthetase complex reflects a defined structure
that also pre-exists in the cell and that the 38-kDa polypeptide is an integral component of this complex.