Characterization of a unique enzyme complex composed of S-adenosyl-L-methionine-tRNA-methyltransferase and aminoacyl-tRNA synthetase activities
Year: 1977
Type: article
Abstract: S-adenosyl-L-methionine-tRNA methyltransferases of a murine leukemia cell line were found to exist in a high molecular weight enzyme complex. Aminoacyl-tRNA synthetase activity always co-chromatographed and co-sedimented with methyltransferase activity in evidence of a unique association of these two groups of enzymes. Molecular weight studies showed a probable molecular weight of 9 X 10(5) daltsons for the intact complex which dissociates to complexes of 6 X 10(5) and 3 X 10(5) daltons. The complexes contain discrete polypeptides of 25,000-90,000 daltons as determined from SDS-gel electrophoresis. High resolution fatty acid analysis showed that only very small amounts of saponifiable lipids were associated with the purified enzyme complex. Similarly very little protein-bound sugars was found within the complex indicating that neither lipids nor sugars were involved in the protein-protein interactions of the complex. Analysis of tRNA methylated in vitro indicated the presence of most methyltransferase activities in the purified complex. Of note was the absence from the complex of the methyltransferase responsible for the production of ribo Tp.
Source: Nucleic Acids Research
Authors: Paul F. Agris, David Setzer, Charles W. Gehrke
Institution: University of Missouri
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2087850900