title: Inhibition of the initiation of translation by a factor isolated from Escherichia coli cells.
abstract: A low molecular weight factor isolated from Escherichia coli cells was found to inhibit protein synthesis in vitro directed by RNA of bacteriophage R-17. The factor also inhibited poly(U)-directed translation, but higher concentrations were required. When the factor was added after R-17 RNA-directed translation was initiated, the onset of inhibition was delayed. Initiation-independent translation of polysomes was not inhibited. The factor inhibited the binding of N-formylmethionyl-tRNAfMet to 70S ribosomes to form the 70S initiation complex, and it released the N-flrmylmethionyl-tRNAfMet from preformed complexes. The factor did not prevent the formation of N-formylmethionylpuromycin. It was concluded that the factor inhibits specifically the initiation of translation.
mesh_terms: D002474:Cell-Free System; D004926:Escherichia coli / Q000235:genetics*; D009239:N-Formylmethionine; D010441:Peptide Chain Elongation, Translational / Q000187:drug effects; D010442:Peptide Chain Initiation, Translational / Q000187:drug effects; D011132:Polyribosomes / Q000187:drug effects; D014176:Protein Biosynthesis / Q000187:drug effects*; D012333:RNA, Messenger / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D012346:RNA, Transfer, Amino Acyl; D009239:N-Formylmethionine