Free fatty acids associated with the high molecular weight aminoacyl-tRNA synthetase complex influence its structure and function.
نویسندگان
چکیده
Aminoacyl-tRNA synthetases from higher eukaryotes often are isolated as high molecular weight complexes associated with other components such as lipids. Since hydrophobic interactions are involved in the organization of the complex, it has been suggested that interaction of synthetases with these lipids might be important for their structure and function. Delipidation is known to affect certain properties of synthetases within the complex including sensitivity to detergents plus salts, temperature inactivation, hydrophobicity, sensitivity to proteases, and, as shown here, sensitivity to p-mercuribenzoate and sites of papain cleavage. Of the lipids known to co-purify with the complex, cholesterol esters, phospholipids and free fatty acids, we show that the particular lipids responsible for many of these changes are the free fatty acids. Specific removal of fatty acids results in a complex with properties similar to one totally delipidated by detergent treatment, and readdition of the fatty acid fraction reverses the effects. The fatty acid fraction contains both saturated and unsaturated fatty acids, but unsaturated fatty acids are much more effective in reversing the properties of the delipidated complex that are saturated fatty acids. These results indicate that the free fatty acids co-purifying with the synthetase complex bind to the synthetases and affect their structure and function.
منابع مشابه
The eucaryotic aminoacyl-tRNA synthetase complex: suggestions for its structure and function
Aminoacyl-tRNA synthetases from eucaryotic cells generally are isolated as high molecular weight complexes comprised of multiple synthetase activities, and often containing other components as well. A model is proposed for the synthetase complex in which hydrophobic extensions on the proteins serve to maintain them in their high molecular weight form, but are not needed for catalytic activity. ...
متن کاملMutation in Aminoacyl Trna Synthetase 1 In Autosomal Recessive Intellectual Disability
Background: Intellectual disability (ID) is one of the most common neurodevelopment disorders that caused by both environment and genetic factors. Also genetic defects have involving for approximately 50% of ID etiology, it is demonstrated that genetics play significant role in ID development. The important risk factor in most country in ID is consanguinity marriage. Iran has high frequency of ...
متن کاملHigh-molecular-weight forms of aminoacyl-tRNA synthetases and tRNA modification enzymes in Escherichia coli.
The presence of high-molecular-weight complexes of aminoacyl-tRNA synthetases in Escherichia coli has been reported (C. L. Harris, J. Bacteriol. 169:2718-2723, 1987). In the current study, Bio-Gel A-5M gel chromatography of 105,000 x g supernatant preparations from E. coli Q13 indicated high molecular weights for both tRNA methylase (300,000) and tRNA sulfurtransferase (450,000). These tRNA mod...
متن کاملStoichiometry 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 کاملTwo isomorphous heavy-atom derivatives of crystalline methionyl-tRNA synthetase from Escherichia coli.
Aminoacyl-tRNA synthetases play a key role in the biosynthesis of proteins by their ability to specifically recognize an amino acid and its corresponding tRNA. An understanding of the basis of such specific proteinnucleic acid recognition requires the knowledge of the structure of the molecules involved. This goal is probably not very remote now since a high resolution model of yeast phenylalan...
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:
- The Journal of biological chemistry
دوره 265 10 شماره
صفحات -
تاریخ انتشار 1990