title: DNA-directed synthesis in vitro of beta-galactosidase: requirement for a ribosome release factor.
abstract: The DNA-directed synthesis of beta-galactosidase in Escherichia coli extracts has been investigated in a partially fractionated system. A dependency was obtained for 3',5'-cyclic AMP receptor protein and also for a factor, from the salt wash of ribosomes, that has been purified to near homogeneity. This factor has been identified with a ribosome release factor previously purified from the supernatant fraction by A. Hirashima and A. Kaji [(1972) Biochemistry 11,4037-4044]. In the coupled transcription-translation system this factor stimulates beta-galactosidase synthesis and total protein synthesis 2- to 4-fold. It is thus clear that the ribosome release factor has a physiological function in translation. It may also affect transcription, because it stimulated total RNA synthesis up to 50% in this in vitro system.
mesh_terms: D003429:Cross Reactions; D004269:DNA, Bacterial / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D005696:Galactosidases / Q000096:biosynthesis*; D005779:Immunodiffusion; D007700:Kinetics; D008970:Molecular Weight; D010443:Peptide Chain Termination, Translational; D011132:Polyribosomes / Q000378:metabolism; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D011953:Receptors, Cyclic AMP / Q000378:metabolism; D012269:Ribosomal Proteins / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000096:biosynthesis*
chemical_list: D004269:DNA, Bacterial; D012333:RNA, Messenger; D011953:Receptors, Cyclic AMP; D012269:Ribosomal Proteins; D005696:Galactosidases; D001616:beta-Galactosidase