title: Stimulatory factor for tRNA aminoacylation: possible product of modifier genes in Drosophila melanogaster.
abstract: A factor which stimulates the aminoacylation of heterologous and homologous tRNAs for lysine and leucine, as well as a mixture of amino acids, has been isolated from cytoplasmic extracts in Drosophila. The stimulatory factor is separated from inorganic pyrophosphatase activity by DEAE-cellulose chromatography and from aminoacyl-tRNA synthetase activity by trichloroacetic acid precipitation. It contains no nucleotidyl transferase activity. It is trypsin-sensitive and heat-stable, indicating that it may be a small protein. Attempts to measure the molecular weight, however, indicate heterogeneity in size, ranging from 20,000 to 65,000. The A53g mutant has four times as much factor Ore-R adults at 0-2 days; by 6-8 days the level has declined to less than one and a half times that of Ore-R. The heightened aminoacylation activity in the mutant extract is accompanied by increased soluble protein levels. It is known that the stimulation of tRNA aminoacylation in A53g is controlled by modifier genes which enhance the expression of the A53g mutant. The possibility that the stimulation factor is a product of the modifier genes is examined.
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D005796:Genes; D006358:Hot Temperature; D066298:In Vitro Techniques; D008250:Lysine-tRNA Ligase / Q000378:metabolism; D008970:Molecular Weight; D009713:Nucleotidyltransferases / Q000378:metabolism; D011506:Proteins / Q000302:isolation & purification*; D012346:RNA, Transfer, Amino Acyl / Q000096:biosynthesis*; D014357:Trypsin
chemical_list: D011506:Proteins; D012346:RNA, Transfer, Amino Acyl; D009713:Nucleotidyltransferases; D014357:Trypsin; D008250:Lysine-tRNA Ligase