title: Purification and properties of a soluble factor required for the deoxyribonucleic acid-directed in vitro synthesis of beta-galactosidase.
abstract: The DNA-directed in vitro synthesis of beta-galactosidase has been investigated in a system dependent on Escherichia coli ribosomes, a salt wash of the ribosomes, and a supernatant fraction. Fractionation of the supernatant has made it possible to obtain dependencies on RNA polymerase and another protein factor for beta-galactosidase synthesis. The other factor (called L factor) cannot be replaced by a variety of proteins known to be required for transcription and translation. It has been purified to homogeneity and has a molecular weight of approximately 65,000. Although it is required for the in vitro synthesis of beta-galactosidase, it has no effect on total DNA-dependent amino acid incorporation under the conditions of the incubation. However, total RNA synthesis is depressed by the addition of L factor in a manner similar to what is observed with rho factor could not replace L factor in beta-galactosidase synthesis.
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D004269:DNA, Bacterial; D012321:DNA-Directed RNA Polymerases / Q000302:isolation & purification / Q000378:metabolism; D004355:Drug Stability; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology*; D005696:Galactosidases / Q000096:biosynthesis*; D006358:Hot Temperature; D007700:Kinetics; D010445:Peptide Elongation Factors; D014176:Protein Biosynthesis; D012270:Ribosomes / Q000201:enzymology; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D010445:Peptide Elongation Factors; D012321:DNA-Directed RNA Polymerases; D005696:Galactosidases; D000604:Amino Acyl-tRNA Synthetases