Characterization of a Homogeneous Arginyl- and Lysyl-tRNA Synthetase Complex Isolated from Rat Liver
نویسنده
چکیده
Bisubstrate kinetics and end product and dead end inhibition studies were performed on lysyl-tRNA synthetase isolated from rat liver. The kinetic patterns obtained are consistent with a sequential ordered mechanism of substrate addition, tRNA bound first, followed by lysine, and then by ATP. Pyrophosphate and AMP are released in a random fashion with aminoacylated tRNA the last product to dissociate from the enzyme. This is the first report of a kinetic mechanism for lysyl-tRNA synthetase.
منابع مشابه
Stoichiometry and composition of an aminoacyl-tRNA synthetase complex from rat liver.
The particulate aminoacyl-tRNA synthetases of rat liver were copurified about 1000-fold with more than 20% yields for individual synthetase activities. Measurements of aminoacylation activities showed that lysyl-, arginyl-, leucyl-, isoleucyl-, and methionyl-tRNA synthetases in the purified complex cosedimented at 18 S. The molecular weight of the synthetase complex is about one million, as est...
متن کاملIsolation and electron microscopic characterization of the high molecular mass aminoacyl-tRNA synthetase complex from murine erythroleukemia cells.
A high molecular mass aminoacyl-tRNA synthetase complex has been isolated from a murine erythroleukemia cell line. This multienzyme complex contains activities for the arginyl-, aspartyl-, glutamyl-, glutaminyl-, isoleucyl,- leucyl-, lysyl-, methionyl-, and prolyl-tRNA synthetases. This enzyme composition, the polypeptide pattern observed upon sodium dodecyl sulfate-polyacrylamide gel electroph...
متن کاملExistence of two forms of rat liver arginyl-tRNA synthetase suggests channeling of aminoacyl-tRNA for protein synthesis.
Arginyl-tRNA synthetase (arginine-tRNA ligase, EC 6.1.1.19) is found in extracts of mammalian cells both as a free protein (Mr = 60,000) and as a component (Mr approximately 72,000) of the high molecular weight aminoacyl-tRNA synthetase complex (Mr greater than 10(6). Several pieces of evidence indicate that the low molecular weight free form is not a proteolytic degradation product of the comp...
متن کاملEvidence for similar structural organization of the multienzyme aminoacyl-tRNA synthetase complex in vivo and in vitro.
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 th...
متن کاملHuman tryptophanyl-tRNA synthetase is switched to a tRNA-dependent mode for tryptophan activation by mutations at V85 and I311
For most aminoacyl-tRNA synthetases (aaRS), their cognate tRNA is not obligatory to catalyze amino acid activation, with the exception of four class I (aaRS): arginyl-tRNA synthetase, glutamyl-tRNA synthetase, glutaminyl-tRNA synthetase and class I lysyl-tRNA synthetase. Furthermore, for arginyl-, glutamyl- and glutaminyl-tRNA synthetase, the integrated 3' end of the tRNA is necessary to activa...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2001