Valyl-tRNA synthetase from rabbit liver. I. Purification as a heterotypic complex in association with elongation factor 1.
Valyl-tRNA synthetase occurs as a high molecular mass entity of approximately equal to 700 kDa in the crude extract from rabbit liver. The enzyme was purified as a heterotypic complex comprising four polypeptides of 140, 50, 35, and 27 kDa in the molar proportions of 1:2:1:1, respectively, as determined by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Co-purification of these components at each step of the purification supports the conclusion that they are physically associated within the same complex. In addition to valyl-tRNA synthetase activity, which was assigned to the 140-kDa component, the purified complex exhibits a potent Elongation Factor 1 activity, determined by its ability to sustain poly(U)-dependent polyphenylalanine synthesis in the presence of Elongation Factor 2. Our results are essentially in agreement with those from a recent report (Motorin, Y., Wolfson, A., Orlovsky, A., and Gladilin, K. (1988) FEBS Lett. 238, 262-264), according to which the polypeptides other than that assigned to valyl-tRNA synthetase correspond to the subunits of Elongation Factor 1H.
Bec
G
G
Laboratoire d'Enzymologie, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.
Kerjan
P
P
Zha
X D
XD
Waller
J P
JP
D000604:Amino Acyl-tRNA Synthetases / Q000302:isolation & purification*; D000818:Animals; D002845:Chromatography; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D017886:Durapatite; D004591:Electrophoresis, Polyacrylamide Gel; D006882:Hydroxyapatites; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D008970:Molecular Weight; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors / Q000302:isolation & purification* / Q000378:metabolism / Q000648:ultrastructure; D011817:Rabbits; D012261:Ribonucleoproteins / Q000302:isolation & purification; D014637:Valine-tRNA Ligase / Q000302:isolation & purification* / Q000378:metabolism
D006882:Hydroxyapatites; D046911:Macromolecular Substances; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors; D012261:Ribonucleoproteins; D017886:Durapatite; D000604:Amino Acyl-tRNA Synthetases; D014637:Valine-tRNA Ligase