title: Photoincorporation of puromycin and N-(ethyl-2-diazomalonyl)puromycin into Escherichia coli ribosomes.
abstract: [3H]Puromycin and N-(ethyl-2-diazomalonyl)[3H]puromycin are incorporated into E. coli ribosomes on irradiation at 253.7 nm. Both compounds incorporate into both protein and nucleic acid. Two-dimensional gel electrophoresis of ribosomal protein shows that L23 is the major protein labeled by puromycin. Although incorporation is clearly a complex process, evidence is presented that L23 is labeled via an affinity labeling process, thus placing L23 at the aminoacyl-tRNA receptor (A) site. N-(ethyl-2-diazomalonyl)puromycin is a ribosomal ligand, as shown by its inhibition of two ribosomal assays, but it is not a good puromycin analog, and it is unclear whether its incorporation, which proceeds via both carbene-dependent and carbene-independent processes, results from affinity labeling.
mesh_terms: D001391:Azo Compounds / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D007700:Kinetics; D008314:Malonates / Q000378:metabolism; D010777:Photochemistry; D011691:Puromycin / Q000031:analogs & derivatives* / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D001391:Azo Compounds; D008314:Malonates; D012269:Ribosomal Proteins; D011691:Puromycin