Effects of erythromycin on membrane-bound chloroplast ribosomes from wild-type Chlamydomonas reinhardi and erythromycin-resistant mutants.
1. Treatment of wild-type cells of Chlamydomonas reinhardi with high concentrations of erythromycin results in increased recovery of membrane-bound chloroplast ribosomes, presumably by preventing polysomal runoff during harvesting of cells. No such membrane-retention effect is detected if erythromycin is added after harvesting of cultures, before cell breakage. 2. Growth of wild-type cells is inhibited by 10 microgram/ml erythromycin, but a concentration twice as high is required to increase recovery of membrane-bound wild-type ribosomes. On the other hand, the concentrations of erythromycin which inhibit growth of mutant ery-M1b produce a membrane-retention effect. Mutant ery-U1a is resistant to high concentrations of erythromycin and no membrane-retention effect is detectable at concentrations which produce one in wild type and ery-M1b. 3. These results can be reconciled by a two-point model of the mechanism of erythromycin action on chloroplast ribosomes in Chlamydomonas.
D002696:Chlamydomonas; D002736:Chloroplasts / Q000187:drug effects* / Q000648:ultrastructure; D004352:Drug Resistance, Microbial; D004917:Erythromycin / Q000378:metabolism / Q000494:pharmacology*; D008566:Membranes / Q000187:drug effects; D009154:Mutation; D012270:Ribosomes / Q000187:drug effects* / Q000378:metabolism
D004917:Erythromycin